CLOUD-392 Pin Github Actions to release SHA

Author: michelesr

.github/workflows/publish.yml

@@ -17,7 +17,7 @@ jobs:
     runs-on: ubuntu-22.04
     steps:
       - name: Build and push to ECR
-        uses: citizensadvice/build-and-push-action@v2
+        uses: citizensadvice/build-and-push-action@be6164e42eb03fee4e31e49b0e202a77d164d6d5
         with:
           aws_access_key: ${{ secrets.PUBLIC_PUSH_ECR_AWS_KEY }}
           aws_secret_key: ${{ secrets.PUBLIC_PUSH_ECR_AWS_SECRET }}

.github/workflows/test.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Git Checkout
-        uses: actions/checkout@v6
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd
       - name: Build
         run: |
           docker build -t postcoder .