Add validate-resolved-languages.yml

This workflow checks that src/resolved-languages.json exists and is
up-to-date with respect to the default (linked) CodeQL version.

Author: cklin

.github/workflows/validate-resolved-languages.yml

@@ -0,0 +1,76 @@
+name: Validate Resolved Languages File
+env:
+  GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+  GO111MODULE: auto
+on:
+  push:
+    branches:
+      - main
+      - releases/v*
+  pull_request:
+    types:
+      - opened
+      - synchronize
+      - reopened
+      - ready_for_review
+  schedule:
+    - cron: '0 5 * * *'
+  workflow_dispatch:
+    inputs: {}
+  workflow_call:
+    inputs: {}
+defaults:
+  run:
+    shell: bash
+jobs:
+  validate-resolved-languages:
+    name: Validate Resolved Languages File
+    permissions:
+      contents: read
+      security-events: read
+    timeout-minutes: 10
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out repository
+        uses: actions/checkout@v5
+      - name: Install Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: 20.x
+          cache: npm
+      - name: Install dependencies
+        run: npm ci
+      - name: Prepare test
+        id: prepare-test
+        uses: ./.github/actions/prepare-test
+        with:
+          version: linked
+          use-all-platform-bundle: 'false'
+          setup-kotlin: 'false'
+      - name: Initialize CodeQL
+        id: init
+        uses: ./../action/init
+        with:
+          tools: ${{ steps.prepare-test.outputs.tools-url }}
+      - name: Verify that the resolved languages file is up to date
+        env:
+          CODEQL: ${{ steps.init.outputs.codeql-path }}
+          RESOLVED_LANGUAGES_FILE: ../action/src/resolved-languages.json
+        run: |
+          if [ ! -f "${RESOLVED_LANGUAGES_FILE}" ]; then
+            echo "::error file=src/resolved-languages.json::The resolved-languages.json file is missing."
+            exit 1
+          fi
+          "${CODEQL}" resolve languages --format=betterjson --extractor-include-aliases > resolved-languages.json
+          if ! diff -u resolved-languages.json "${RESOLVED_LANGUAGES_FILE}"; then
+            echo "::error file=src/resolved-languages.json::The saved resolved-languages.json file is out of date."
+            exit 1
+          fi
+      - name: Upload resolved languages file for debugging
+        if: ${{ failure() }}
+        uses: actions/upload-artifact@v4
+        with:
+          name: resolved-languages
+          path: resolved-languages.json
+    env:
+      CODEQL_ACTION_TEST_MODE: true