fix(ci): replace unavailable PowerShell action

Author: hypnguyen1209

.github/workflows/sync-check.yml

@@ -10,13 +10,11 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - name: Install PowerShell
-        uses: microsoft/powershell@v1
-      - name: Sync check
-        run: pwsh scripts/sync-check.ps1
-      - name: Frontmatter validate
-        run: pwsh scripts/validate-frontmatter.ps1
-      - name: Install mermaid-cli
-        run: npm install -g @mermaid-js/mermaid-cli
-      - name: Validate mermaid
-        run: pwsh scripts/validate-mermaid.ps1
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 22
+          cache: npm
+      - name: Install dependencies
+        run: npm ci
+      - name: Validate sync, frontmatter, and Mermaid
+        run: npm run lint

scripts/ci-config.test.mjs

@@ -17,6 +17,17 @@ test("deploy workflow uses valid expressions and runs its lint dependency on eve
   assert.doesNotMatch(lintMatch.groups.body, /^\s+if:/m);
 });
 
+test("PR sync workflow uses the repository Node validation pipeline", async () => {
+  const workflow = await readFile(
+    new URL(".github/workflows/sync-check.yml", repositoryRoot),
+    "utf8",
+  );
+
+  assert.doesNotMatch(workflow, /microsoft\/powershell/);
+  assert.match(workflow, /run:\s+npm ci/);
+  assert.match(workflow, /run:\s+npm run lint/);
+});
+
 test("Mermaid validation supplies the documented Chromium CI sandbox override", async () => {
   const validator = await readFile(
     new URL("scripts/validate-mermaid.mjs", repositoryRoot),