T8218: Updated workflows for pullrequest_target policy change

[kumvijaya]

Proposed Commit Message

This PR updates pull_request_target workflows to comply with GitHub's recent policy change announced on November 7, 2025 Actions: pull_request_target and environment branch protections changes.

Background
GitHub updated how pull_request_target workflows are evaluated. Previously, these workflows were evaluated using the PR's target branch. Now, they are always evaluated using the repository's default branch (current). This means branch-filtered workflows will only trigger reliably if they exist and match on the default branch.

Changes
Updated the workflows to include all supported branches in their pull_request_target trigger:

Since pull_request_target workflows are now evaluated from the default branch, the workflow file must exist unchanged on the default branch. To support branch-specific triggering across all maintained branches (current, circinus, sagitta), the branch filters must explicitly list all branches or be removed entirely.

These changes ensure that:
Workflows trigger correctly for PRs targeting any of the three supported branches
The workflow files are evaluated from the current branch as per GitHub's new requirement

Note:
As these workflows doesn't have any branch-specific logic, no changes needed apart from this.

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Additional Context

Test Steps

Checklist:

• My code follows the process laid out in the documentation
• I have updated or added any unit tests accordingly
• I have updated or added any documentation accordingly

[asklymenko]

Modify workflow to use new "pullrequest_target" policy.

[dmbaturin]

I don't see obvious issues and I trust @asklymenko's judgement.