chore(ci): add special branches for testing build_deploy, fix lib-injection [backport #5486 to 1.11] (#5487)

In order to test build_deploy jobs a special branch pattern is added.

Github doesn't verify that jobs adhere to its workflow schema until the
job matches the `on` criteria and is run. Previously this workflow only
ran on release branches and on releases. This meant that there was no
way to ensure the jobs actually parsed correctly before a PR was merged
or a release was done.


To demonstrate the fix, a bug exists in the lib-injection job which
results in



![image](https://user-images.githubusercontent.com/6321485/230226834-4e5bc217-9dd9-4925-8d0c-cf75c4657910.png)

on the first commit of this PR.

A commit is pushed with the fix which shows that the workflow at least
parses:



![image](https://user-images.githubusercontent.com/6321485/230227458-1c2ef63c-48f0-4ee7-8795-780ffc68eb4a.png)


This of course doesn't verify that the job runs successfully but it at
least lets us know that it loads fine (which given Github's workflow
rules and lack of documentation goes a long way).

## Checklist

- [x] Change(s) are motivated and described in the PR description.
- [x] Testing strategy is described if automated tests are not included
in the PR.
- [x] Risk is outlined (performance impact, potential for breakage,
maintainability, etc).
- [x] Change is maintainable (easy to change, telemetry, documentation).
- [x] [Library release note
guidelines](https://ddtrace.readthedocs.io/en/stable/contributing.html#Release-Note-Guidelines)
are followed.
- [x] Documentation is included (in-code, generated user docs, [public
corp docs](https://github.com/DataDog/documentation/)).
- [x] PR description includes explicit acknowledgement/acceptance of the
performance implications of this PR as reported in the benchmarks PR
comment.

## Reviewer Checklist

- [x] Title is accurate.
- [x] No unnecessary changes are introduced.
- [x] Description motivates each change.
- [x] Avoids breaking
[API](https://ddtrace.readthedocs.io/en/stable/versioning.html#interfaces)
changes unless absolutely necessary.
- [x] Testing strategy adequately addresses listed risk(s).
- [x] Change is maintainable (easy to change, telemetry, documentation).
- [x] Release note makes sense to a user of the library.
- [x] Reviewer has explicitly acknowledged and discussed the performance
implications of this PR as reported in the benchmarks PR comment.

Author: Kyle-Verhoog

.github/workflows/build_deploy.yml

@@ -5,6 +5,9 @@ on:
     branches:
       - '[0-9].[0-9]*'
       - '[0-9].x'
+      # special branches used to test this workflow
+      # before merging/releasing
+      - build_deploy*
   pull_request:
     paths:
       - "setup.py"
@@ -214,7 +217,6 @@ jobs:
 
   build-and-publish-init-image:
     needs: [upload_pypi]
-    runs-on: ubuntu-latest
     uses: ./.github/workflows/lib-inject-publish.yml
     secrets:
       token: ${{ secrets.GITHUB_TOKEN }}