ci(new workflow): Run tests on master every 12 hours

.github/workflows/periodic-coverage.yml

@@ -0,0 +1,48 @@
+# Periodically runs the tests on master and posts coverage results to codecov.
+
+name: Test with coverage
+on:
+  workflow_dispatch: {}
+  schedule:
+    # Run every 12 hours.
+    - cron: '0 */12 * * *'
+
+concurrency:
+  group: ${{ github.workflow }}
+  cancel-in-progress: true
+
+defaults:
+  run:
+    shell: bash
+
+jobs:
+
+  info:
+    name: info
+    uses: ./.github/workflows/ci-info.yml
+    permissions:
+      contents: read
+    with:
+      ref: master
+      is-snapshot: true
+    secrets: inherit
+
+  ci:
+    name: CI
+    needs: [info]
+    uses: ./.github/workflows/ci.yml
+    permissions:
+      contents: read
+      # To sign artifacts.
+      id-token: write
+    with:
+      ref: master
+      version: ${{ needs.info.outputs.version }}
+      lint: true
+      build-all-targets: true
+      test-codegen:  true
+      test-version-sets: current
+      integration-test-platforms: ubuntu-latest
+      acceptance-test-platforms: macos-latest windows-latest
+      enable-coverage: true
+    secrets: inherit