update the prod image tag (#15848)

Signed-off-by: Basma1912 <basad@mozilla.com>

.github/workflows/build-and-push.yml

@@ -127,7 +127,7 @@ jobs:
         if: startsWith(github.ref, 'refs/tags/')
         run: |
 
-          echo TAG="$(git describe --tags --abbrev=7)" >> "$GITHUB_ENV"
+          echo TAG="prod-$(git rev-parse HEAD)" >> "$GITHUB_ENV"
           # Version tags are deployed to prod.
           echo DEPLOYMENT_ENV=prod >> "$GITHUB_ENV"
           echo DEPLOYMENT_REALM=prod >> "$GITHUB_ENV"