Fix issue bot triggering on PRs and closed issues

[kacperkapusciak]

Summary:

This PR fixes a bug with an issue labeling bot issues triggering on comments to pull requests. The action doesn't trigger when a pull request is open (but other actions add comments immediately).

From GitHub docs:

GitHub's REST API considers every pull request to be an issue, but not every issue is a pull request. [...] Pull requests have a pull_request property in the issue object.

☝️ Which is a way to differentiate between an issue and a pull request

Relates to a bug introduced in #38338 and links to ☂️#35591

Changelog:

[INTERNAL] [FIXED] - Prevent issue bot triggering on pull requests

Test Plan:

This PR makes use of github.event.issue.pull_request object which is null on issues and comments in issues:

and truthy on comments on pull requests

With a change from PR bot skips execution on comments on pull requests

[analysis-bot]

Platform	Engine	Arch	Size (bytes)	Diff
android	hermes	arm64-v8a	8,842,288	-1,533
android	hermes	armeabi-v7a	8,151,608	-1,338
android	hermes	x86	9,347,958	-1,631
android	hermes	x86_64	9,190,784	-1,553
android	jsc	arm64-v8a	9,454,278	-1,309
android	jsc	armeabi-v7a	8,635,602	-1,122
android	jsc	x86	9,537,280	-1,395
android	jsc	x86_64	9,780,636	-1,337

Base commit: 216865c
Branch: main

[facebook-github-bot]

@cortinico has imported this pull request. If you are a Meta employee, you can view this diff on Phabricator.

[github-actions]

This pull request was successfully merged by @kacperkapusciak in 5705661.

^{When will my fix make it into a release? | Upcoming Releases}