ci: add Github Actions workflow to run checks

Author: ahal

.github/workflows/deploy.yml

@@ -0,0 +1,26 @@
+name: deploy
+on:
+  workflow_run:
+    workflows: ["validate"]
+    branches: ["main"]
+    types:
+      - completed
+
+jobs:
+  deploy:
+    runs-on: ubuntu-latest
+    environment: deploy-${{matrix.environment}}
+    strategy:
+      matrix:
+        environment: ["staging"]  # TODO Add 'firefoxci' when we're ready to switch over.
+    steps:
+      - uses: actions/checkout@v4
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.11'
+          cache: pip
+      - name: Install dependencies
+        run: pip install -r requirements/base.txt
+      - name: Deploy environment
+        run: tc-admin apply --environment ${{matrix.environment}}

.github/workflows/validate.yml

@@ -0,0 +1,23 @@
+name: validate
+on: [push]
+
+jobs:
+  check:
+    runs-on: ubuntu-latest
+    environment: validate-${{matrix.environment}}
+    strategy:
+      matrix:
+        environment: ["staging", "firefoxci"]
+    env:
+      TASKCLUSTER_ROOT_URL: ${{vars.TASKCLUSTER_ROOT_URL}}
+    steps:
+      - uses: actions/checkout@v4
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.11'
+          cache: pip
+      - name: Install dependencies
+        run: pip install -r requirements/test.txt
+      - name: Run checks
+        run: tc-admin check --environment ${{matrix.environment}}