fix: add back pin for setup-protoc (#3759)

Author: mrkaye97

.github/workflows/test.yml

@@ -20,7 +20,7 @@ jobs:
       - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
 
       - name: Install Protoc
-        uses: arduino/setup-protoc
+        uses: arduino/setup-protoc@c65c819552d16ad3c9b72d9dfd5ba5237b9c906b # v3.0.0
         with:
           version: "29.3"
           repo-token: ${{ secrets.GITHUB_TOKEN }}