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

Author: renovate[bot]

.github/workflows/unit-testing.yml

@@ -10,7 +10,7 @@ jobs:
   deploy:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4
       - uses: pnpm/action-setup@v2.2.4
         with:
           version: 6.23.x