Clean up docs and workflows after submodule removal (#6904)

Follow up that I forgot to push to the
#6898 PR.

- Stops setting up the submodule in GitHub workflows.
- Stops checking if the submodule is up to date with dependabot.
- Doesn't try to initialize the submodule in Firebase Studio.
- Remove the instructions around the submodule from the README

Author: parlough

.github/dependabot.yml

@@ -21,10 +21,3 @@ updates:
       - "auto.dependencies"
       - "auto.npm"
       - "lang.javascript"
-  - package-ecosystem: "gitsubmodule"
-    directory: "/"
-    schedule:
-      interval: "daily"
-    labels:
-      - "auto.dependencies"
-      - "auto.submodules"

.github/workflows/build.yml

@@ -26,8 +26,6 @@ jobs:
     timeout-minutes: 30
     steps:
       - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8
-        with:
-          submodules: recursive
       - uses: dart-lang/setup-dart@e51d8e571e22473a2ddebf0ef8a2123f0ab2c02c
         with:
           sdk: beta

.github/workflows/test.yml

@@ -33,8 +33,6 @@ jobs:
     continue-on-error: ${{ matrix.experimental }}
     steps:
       - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8
-        with:
-          submodules: recursive
       - uses: dart-lang/setup-dart@e51d8e571e22473a2ddebf0ef8a2123f0ab2c02c
         with:
           sdk: ${{ matrix.sdk }}
@@ -56,8 +54,6 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8
-        with:
-          submodules: recursive
       - uses: dart-lang/setup-dart@e51d8e571e22473a2ddebf0ef8a2123f0ab2c02c
         with:
           sdk: beta
@@ -71,8 +67,6 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8
-        with:
-          submodules: recursive
       - uses: dart-lang/setup-dart@e51d8e571e22473a2ddebf0ef8a2123f0ab2c02c
         with:
           sdk: beta
@@ -86,8 +80,6 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8
-        with:
-          submodules: recursive
       - uses: dart-lang/setup-dart@e51d8e571e22473a2ddebf0ef8a2123f0ab2c02c
         with:
           sdk: beta
@@ -101,8 +93,6 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8
-        with:
-          submodules: recursive
       - uses: dart-lang/setup-dart@e51d8e571e22473a2ddebf0ef8a2123f0ab2c02c
         with:
           sdk: beta

.idx/dev.nix

@@ -38,7 +38,6 @@
     workspace = {
       # Runs when a workspace is first created
       onCreate = {
-        get-submodule = "git submodule update --init --recursive";
         dart-pub-get = "dart pub get";
       };
       # Runs when the workspace is (re)started

README.md

@@ -33,10 +33,6 @@ you probably don't need to build this site.
 Often you can make changes using the GitHub UI.
 We can stage the changes automatically in your pull request.
 
-> [!IMPORTANT]  
-> If you are cloning this repository locally,
-> follow the below instruction on cloning with its submodule.
-
 If your change involves code samples, adds/removes pages, or affects navigation,
 do consider building and testing your work before submitting.
 
@@ -66,49 +62,28 @@ and already the latest stable version:
 dart --version
 ```
 
-### Clone this repo and its submodules
-
-> [!NOTE]
-> This repository has git _submodules_, which affects how you clone it.
-> The GitHub documentation has general help on
-> [forking][] and [cloning][] repos.
+### Clone this repo
 
 If you're not a member of the Dart organization,
-we recommend you **create a fork** of this repo under your own account,
+we recommend you [create a fork][] of this repo under your own account,
 and then submit a PR from that fork.
 
 Once you have a fork (or you're a Dart org member),
-_choose one_ of the following submodule-cloning techniques:
-
-1. Clone the repo and its submodule at the same time
-   using the `--recurse-submodules` option:
-
-   ```terminal
-   git clone --recurse-submodules https://github.com/dart-lang/site-www.git
-   ```
-
-2. If you've already cloned the repo without its submodule,
-   then run this command from the root of the repository:
+clone the repository with `git clone`:
 
-   ```terminal
-   git submodule update --init --recursive
-   ```
+```bash
+git clone https://github.com/dart-lang/site-www.git
+```
 
-> [!NOTE]
-> At any time during development
-> you can use the `git submodule` command to refresh submodules:
->
-> ```terminal
-> git pull && git submodule update --init --recursive
-> ```
+[create a fork]: https://docs.github.com/pull-requests/collaborating-with-pull-requests/working-with-forks/fork-a-repo
 
 ## Set up your local environment and serve changes
 
 Before you continue setting up the site infrastructure,
 verify the correct version of Dart is set up and available by
 following the instructions in [Get the prerequisites](#get-the-prerequisites).
 
-1. _Optional:_ After cloning the repo and its submodules,
+1. _Optional:_ After cloning the repo,
    create a branch for your changes:
 
    ```terminal
@@ -200,8 +175,6 @@ check out the [excerpt updater package documentation][].
 [Build Status SVG]: https://github.com/dart-lang/site-www/workflows/build/badge.svg
 [OpenSSF Scorecard SVG]: https://api.securityscorecards.dev/projects/github.com/dart-lang/site-www/badge
 [Scorecard Results]: https://deps.dev/project/github/dart-lang%2Fsite-www
-[cloning]: https://docs.github.com/repositories/creating-and-managing-repositories/cloning-a-repository
 [Jaspr]: https://jaspr.site
 [Firebase]: https://firebase.google.com/
-[forking]: https://docs.github.com/pull-requests/collaborating-with-pull-requests/working-with-forks/fork-a-repo
 [Repo on GitHub Actions]: https://github.com/dart-lang/site-www/actions?query=workflow%3Abuild+branch%3Amain

cloud_build/deploy.yaml

@@ -1,6 +1,4 @@
 steps:
-  - name: gcr.io/cloud-builders/git
-    args: ['submodule', 'update', '--init', '--recursive']
   - name: gcr.io/cloud-builders/git
     args: [ 'fetch', '--unshallow' ]
   - name: gcr.io/flutter-dev-230821/firebase-ghcli

cloud_build/stage.yaml

@@ -1,6 +1,4 @@
 steps:
-  - name: gcr.io/cloud-builders/git
-    args: ['submodule', 'update', '--init', '--recursive']
   - name: gcr.io/flutter-dev-230821/firebase-ghcli
     # Build the site, deploy it to staging, then comment the link on the PR.
     entrypoint: '/bin/bash'