MWPW-193327 - [infra] make nala test GH runners more stable and robust

[honstar]

Intermittent nala test failures on self-hosted runners were caused by two apt failure modes: unattended-upgrades holding dpkg/apt locks, and transient Ubuntu mirror sync errors during apt-get update.

Add a composite action (.github/actions/prep-apt) that stops background apt services, waits up to 120s for all locks to clear, then runs npx playwright install-deps with up to 3 retries (15s apart).

Apply the composite action to all three self-hosted workflows (run-nala.yml studio job, run-nala-daily.yml, run-nala-milolibs.yaml), replacing the previous unconditional bare install-deps call. Also adds continue-on-error: true to the Playwright cache steps in daily and milolibs, consistent with the studio job.

The GitHub-hosted docs job in run-nala.yml is unchanged — it does not share the self-hosted runner apt environment.

Resolves https://jira.corp.adobe.com/browse/MWPW-193327
QA Checklist: https://wiki.corp.adobe.com/display/adobedotcom/M@S+Engineering+QA+Use+Cases

Please do the steps below before submitting your PR for a code review or QA

• C1. Cover code with Unit Tests
• C2. Add a Nala test (double check with #fishbags if nala test is needed)
• C3. Verify all Checks are green (unit tests, nala tests)
• C4. PR description contains working Test Page link where the feature can be tested
• C5: you are ready to do a demo from Test Page in PR (bonus: write a working demo script that you'll use on Thursday, you can eventually put in your PR)
• C.6 read your Jira one more time to validate that you've addressed all AC's and nothing is missing

🧪 Nala E2E Tests

Nala tests run automatically when you open this PR.

To run Nala tests again:

1. Add the run nala label to this PR (in the right sidebar)
2. Tests will run automatically on the current commit
3. Any future commits will also trigger tests as long as the label remains

To stop automatic Nala tests:

• Remove the run nala label

Note: Tests only run on commits if the run nala label is present. Add the label whenever you need tests to run on new changes.

Test URLs:

• Before: https://main--mas--adobecom.aem.live/
• After: https://mwpw-NUMBER--mas--adobecom.aem.live/

[aem-code-sync]

Hello, I'm the AEM Code Sync Bot and I will run some actions to deploy your branch.
In case there are problems, just click the checkbox below to rerun the respective action.

• Re-sync branch

Commits

• d6e8aaa ✅ (latest)
• f6408c7 ✅
• cc5495c ✅
• 3be153a ✅
• d1ca2c4 ✅
• ac0e44f ✅

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 87.44%. Comparing base (29dc5f3) to head (d6e8aaa).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #771      +/-   ##
==========================================
- Coverage   87.46%   87.44%   -0.02%     
==========================================
  Files         210      210              
  Lines       63081    63081              
==========================================
- Hits        55172    55164       -8     
- Misses       7909     7917       +8     

see 6 files with indirect coverage changes

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[npeltier]

would you mind creating a JIRA and attaching that PR to it?

[honstar]

would you mind creating a JIRA and attaching that PR to it?

Done, ticket created: https://jira.corp.adobe.com/browse/MWPW-193327

Ticket has been created, dismissing review due to absence.