drop 3.7 support (#15234)

end of lifed a couple weeks ago
https://devguide.python.org/versions/

## How I Tested These Changes

bk

Author: alangenfeld

.buildkite/dagster-buildkite/dagster_buildkite/python_version.py

@@ -7,7 +7,6 @@
 
 class AvailablePythonVersion(str, Enum):
     # Ordering is important here, because some steps will take the highest/lowest available version.
-    V3_7 = "3.7"
     V3_8 = "3.8"
     V3_9 = "3.9"
     V3_10 = "3.10"

.buildkite/dagster-buildkite/dagster_buildkite/steps/helm.py

@@ -19,9 +19,9 @@ def build_helm_steps() -> List[BuildkiteStep]:
         os.path.join("helm", "dagster", "schema"),
         unsupported_python_versions=[
             # run helm schema tests only once, on the latest python version
-            AvailablePythonVersion.V3_7,
             AvailablePythonVersion.V3_8,
             AvailablePythonVersion.V3_9,
+            AvailablePythonVersion.V3_10,
         ],
         name="dagster-helm",
         retries=2,

.buildkite/dagster-buildkite/setup.py

@@ -9,7 +9,6 @@
     description="Tools for buildkite automation",
     url="https://github.com/dagster-io/dagster/tree/master/.buildkite/dagster-buildkite",
     classifiers=[
-        "Programming Language :: Python :: 3.7",
         "Programming Language :: Python :: 3.8",
         "Programming Language :: Python :: 3.9",
         "Programming Language :: Python :: 3.10",

docs/content/community/contributing.mdx

@@ -9,7 +9,7 @@ We love to see our community members get involved! If you are planning to contri
 
 ## Environment setup
 
-1. Install Python 3.7 or above.
+1. Install Python 3.8 or above.
 
 2. Create and activate a virtualenv, using the tool of your choice. On macOS you can install `pyenv` with Homebrew:
 

docs/content/dagster-cloud/deployment/serverless.mdx

@@ -147,7 +147,7 @@ if __name__ == "__main__":
 
 ### Using a different Python version
 
-The default version of Python for Serverless deployments is Python 3.8. Versions 3.7, 3.9, 3.10, and 3.11 are also supported. You can specify the version you want by updating your GitHub workflow or using the `--python-version` command line argument:
+The default version of Python for Serverless deployments is Python 3.8. Versions 3.9, 3.10, and 3.11 are also supported. You can specify the version you want by updating your GitHub workflow or using the `--python-version` command line argument:
 
 - **With GitHub**: Change the `python_version` parameter for the `build_deploy_python_executable` job in your `.github/workflows` files. For example:
 

docs/content/getting-started/hello-dagster.mdx

@@ -7,7 +7,7 @@ description: Run dagster for the first time
 
 Welcome to Dagster! In this guide, you'll build a simple data pipeline in Dagster that downloads the top 10 HackerNews stories. In three quick steps, you'll have functional code and begin exploring Dagster's user interface.
 
-**Note**: Before you dive in, make sure you have [Python 3.7+ installed](https://www.python.org/).
+**Note**: Before you dive in, make sure you have [Python 3.8+ installed](https://www.python.org/).
 
 Let's get started!
 

docs/content/getting-started/releases.mdx

@@ -44,6 +44,16 @@ While technically the 0.y.z phase of Semantic Versioning is "anything goes", we
 
 ---
 
+# Python Version Support
+
+Each Dagster release strives to support the currently active versions of python.
+
+When a new version of python is released, Dagster will work to add support once Dagster's own core dependencies have been updated to support it.
+
+When a version of python reaches end of life, Dagster will drop support for it at the next convenient non-patch release.
+
+---
+
 ## Following along
 
 The best way to stay on top of what changes are included in each release is through the [changelog](https://github.com/dagster-io/dagster/blob/master/CHANGES.md). We call out breaking changes in “Breaking Changes” sections and deprecations in “Deprecations” sections.

docs/dagit-screenshot/setup.py

@@ -16,7 +16,6 @@
     description="Utility for taking automated screenshots from dagit",
     classifiers=[
         "Programming Language :: Python :: 3.6",
-        "Programming Language :: Python :: 3.7",
         "Programming Language :: Python :: 3.8",
         "Programming Language :: Python :: 3.9",
         "License :: OSI Approved :: Apache Software License",

docs/next/components/mdx/includes/dagster/DagsterVersion.mdx

@@ -1 +1 @@
-Dagster supports Python 3.7+.
+Dagster supports Python 3.8+.

docs/sphinx/sections/api/apidocs/libraries/dagster-k8s.rst

@@ -59,9 +59,9 @@ For local dev (e.g., on kind or minikube):
 
    helm install \
        --set dagit.image.repository="dagster.io/buildkite-test-image" \
-       --set dagit.image.tag="py37-latest" \
+       --set dagit.image.tag="py310-latest" \
        --set job_runner.image.repository="dagster.io/buildkite-test-image" \
-       --set job_runner.image.tag="py37-latest" \
+       --set job_runner.image.tag="py310-latest" \
        --set imagePullPolicy="IfNotPresent" \
        dagster \
        helm/dagster/
@@ -150,7 +150,7 @@ the repo:
 .. code-block:: shell
 
    ./python_modules/dagster-test/dagster_test/test_project/build.sh 3.7.6 \
-       dagster.io.priv/buildkite-test-image:py37-latest
+       dagster.io.priv/buildkite-test-image:py310-latest
 
 In the above invocation, the Python majmin version should be appropriate for your desired tests.
 
@@ -160,7 +160,7 @@ feedback from the loading process.
 .. code-block:: shell
 
    kind create cluster --name kind-test
-   kind load docker-image --name kind-test dagster.io/dagster-docker-buildkite:py37-latest
+   kind load docker-image --name kind-test dagster.io/dagster-docker-buildkite:py310-latest
 
 If you are deploying the Helm chart with an in-cluster Postgres (rather than an external database),
 and/or with dagster-celery workers (and a RabbitMQ), you'll also want to have images present for