gha: Cancel previous jobs if a PR is updated

Let's make sure we cancel previous runs, mainly as we have some of those
that take a lot of time to run, whenever the PR is updated.

This is based on the following stack overflow suggestion:
https://stackoverflow.com/questions/66335225/how-to-cancel-previous-runs-in-the-pr-when-you-push-new-commitsupdate-the-curre

This is very much needed as we don't want to wait for a long time to
have access to a runner because of other runners are still being used
performing a task that's meaningless due to the PR update.

Fixes: #7298

Signed-off-by: Fabiano Fidêncio <fabiano.fidencio@intel.com>

.github/workflows/payload-after-push.yaml

@@ -5,6 +5,10 @@ on:
       - main
       - stable-*
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
 jobs:
   build-assets-amd64:
     uses: ./.github/workflows/build-kata-static-tarball-amd64.yaml