[fix] Pin GitHub Actions to specific commit SHAs

Fix validate-pins CI check by pinning all unpinned actions to their
exact commit SHA for security and reproducibility.

.github/workflows/release-api-changelogs.yaml

@@ -21,17 +21,17 @@ jobs:
       pull-requests: write
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5.0.1
         with:
           fetch-depth: 0 # Fetch all history for comparing versions
 
       - name: Install pnpm
-        uses: pnpm/action-setup@v4
+        uses: pnpm/action-setup@b906affcce14559ad1aafd4ab0e942779e9f58b1 # v4.3.0
         with:
           version: 10
 
       - name: Setup Node.js
-        uses: actions/setup-node@v5
+        uses: actions/setup-node@a0853c24544627f65ddf259abe73b1d18a591444 # v5.0.0
         with:
           node-version: 'lts/*'
           cache: 'pnpm'