chore(deps): update actions/checkout action to v4 (#27)

Co-authored-by: versionvanguard[bot] <149176998+versionvanguard[bot]@users.noreply.github.com>

Author: versionvanguard[bot]

.github/workflows/firebase-hosting-merge.yml

@@ -13,7 +13,7 @@ jobs:
       name: production
       url: https://bvarga.dev
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - name: Use Node.js ${{ env.NODE_VERSION }}
         uses: actions/setup-node@v2
         with:

.github/workflows/firebase-hosting-pull-request.yml

@@ -9,7 +9,7 @@ jobs:
     runs-on: ubuntu-24.04
     environment: staging
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - name: Use Node.js ${{ env.NODE_VERSION }}
         uses: actions/setup-node@v2
         with: