PLT-621 chore(ci/actions): pin GitHub Actions SHAs (#570)

Author: buschtoens

.github/workflows/ci.yml

@@ -21,9 +21,9 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout Code
-        uses: actions/checkout@v1
+        uses: actions/checkout@50fbc622fc4ef5163becd7fab6573eac35f8462e # v1
       - name: Install Node
-        uses: actions/setup-node@v1
+        uses: actions/setup-node@f1f314fca9dfce2769ece7d933488f076716723e # v1
         with:
           node-version: 16
       - name: Install Dependencies