jjbb: daily job with branch aliases

[v1v]

What does this PR do?

• Support branch aliases for the daily builds
• Update backport (.backportjs and .mergify.yml) with 8.1 and remove 7.16

Why is it important?

Avoid the chances to forget the branch definition in the jjbb, since the cron timer was in the pipelines we could not use a more relax regex.

#2158 is the one enabling 8.1 but with this approach we won't need a similar one when 8.2 is a new branch

[mergify]

This pull request does not have a backport label. Could you fix it @v1v? 🙏
To fixup this pull request, you need to add the backport labels for the needed
branches, such as:

• backport-v./d./d./d is the label to automatically backport to the 7./d branch. /d is the digit
  NOTE: backport-skip has been added to this pull request.

[elasticmachine]

💚 Build Succeeded

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• Start Time: 2022-02-22T15:56:20.193+0000

• Duration: 50 min 33 sec

Test stats 🧪

Test	Results
Failed	0
Passed	253
Skipped	0
Total	253

💚 Flaky test report

Tests succeeded.

🤖 GitHub comments

To re-run your PR in the CI, just comment with:

• /test : Re-trigger the build.

[mergify]

This pull request is now in conflict. Could you fix it @v1v? 🙏
To fixup this pull request, you can check out it locally. See documentation: https://help.github.com/articles/checking-out-pull-requests-locally/

git fetch upstream
git checkout -b feature/use-daily-trigger-job upstream/feature/use-daily-trigger-job
git merge upstream/main
git push upstream feature/use-daily-trigger-job