gha: Manually rebase PR atop of the target branch before testing

We're changing what's been done as part of ac939c458c, as we've
notcied issues using `github.event.pull_request.merge_commit_sha`.

Basically, whenever a force-push would happen, the reference of
merge_commit_sha wouldn't be updated, leading us to test PRs with the
old code. :-/

In order to get the rebase properly working, we need to ensure we pull
the hash of the commit as part of checkout action, and ensure
fetch-depth is set to 0.

Fixes: #7414

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

.github/workflows/run-kata-deploy-tests-on-aks.yaml

@@ -17,6 +17,10 @@ on:
       commit-hash:
         required: false
         type: string
+      target-branch:
+        required: false
+        type: string
+        default: ""
 
 jobs:
   run-kata-deploy-tests:
@@ -45,6 +49,13 @@ jobs:
       - uses: actions/checkout@v3
         with:
           ref: ${{ inputs.commit-hash }}
+          fetch-depth: 0
+
+      - name: Rebase atop of the latest target branch
+        run: |
+          ./tests/git-helper.sh "rebase-atop-of-the-latest-target-branch"
+        env:
+          TARGET_BRANCH: ${{ inputs.target-branch }}
 
       - name: Download Azure CLI
         run: bash tests/functional/kata-deploy/gha-run.sh install-azure-cli