chore: run appinspect api on release branches

[mgrandys-splunk]

Description

Run appinspect api job for release/ branches in build-test-release pipeline
Ticket: https://splunk.atlassian.net/browse/ADDON-77779

Tested in the following cases where appinspect api job is:

• Running for PR with “release/“ base: https://github.com/splunk/splunk-add-on-for-microsoft-cloud-services/actions/runs/13626390125
• Running for manual trigger on “release/“ branch: https://github.com/splunk/splunk-add-on-for-microsoft-cloud-services/actions/runs/13626413937
• Not running for chore/ branch: https://github.com/splunk/splunk-add-on-for-microsoft-cloud-services/actions/runs/13626445165

Checklist

• README.md has been updated or is not required
• push trigger tests
• manual release test
• automated releases test
• pull request trigger tests
• schedule trigger tests
• workflow errors/warnings reviewed and addressed

Testing done

(for each selected checkbox, the corresponding test results link should be listed here)

[dkvashninsplunk]

need to check for base_ref as well when it is a PR to release branch

[mgrandys-splunk]

@dkvashninsplunk Added

[kdoroszko-splunk]

Hi @mgrandys-splunk, could you add some link with test to the description?

[mgrandys-splunk]

Hi @mgrandys-splunk, could you add some link with test to the description?

@kdoroszko-splunk I've updated the description with 3 test cases for MSCS TA pipeline