fix: support workflow_run events for github status and pr comments

[lidel]

adds proper detection of workflow_run events to ensure commit statuses and pr comments are posted to the correct sha when the action is triggered from a workflow_run context (e.g., secure fork pr workflows)

• detect workflow_run event and use workflow_run.head_sha for status
• find pr number from workflow_run context for comments
• update both status and comment sha references

TODO

• merge and release new v1.x.x
• update docs.ipfs.tech to use v1 tag
• update specs.ipfs.tech to use v1 tag

[lidel]

Confirmed it works:

• jobs:
  • https://github.com/ipfs/specs/blob/main/.github/workflows/build.yml
  • https://github.com/ipfs/specs/blob/main/.github/workflows/deploy.yml (triggered once build completes)
• demo:
  • comment on PR from fork: Initial UnixFS specification ipfs/specs#331 (comment)

[Copilot]

Pull Request Overview

This PR adds support for workflow_run events to ensure GitHub commit statuses and PR comments are posted to the correct SHA when the action is triggered from a workflow_run context, particularly for secure fork PR workflows.

• Enhanced SHA detection logic to handle workflow_run events by using workflow_run.head_sha
• Added PR number discovery for workflow_run events by querying the GitHub API
• Updated comment creation/update conditions to support workflow_run events

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 3 comments.

File	Description
action.yml	Enhanced event handling for workflow_run events, added PR discovery logic, and updated comment conditions
CHANGELOG.md	Added changelog entry documenting the new workflow_run event support

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[2color]

Overall looks good to me. See my suggestions

[lidel]

Tested with your suggestions in ipfs/specs and works as expected (ipfs/specs#331 (comment)), I'm going forward with release.