Use SHA instead of version in GHA for code samples

Author: curquiza

.github/workflows/code-sample-automation.yml

@@ -10,7 +10,7 @@ jobs:
   add-pr-to-project:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/add-to-project@v1
+      - uses: actions/add-to-project@f5473ace9aeee8b97717b281e26980aa5097023f
         with:
           project-url: https://github.com/orgs/meilisearch/projects/44
           github-token: ${{ secrets.MEILI_BOT_GH_PAT }}