[release/v7.4] Enhance path filters action to set outputs for all changes when not a PR

Backport of #25367 to release/v7.4

Triggered by @TravisEz13 on behalf of @TravisEz13

Original CL Label: CL-BuildPackaging

/cc @PowerShell/powershell-maintainers

Impact

Choose either tooling or Customer impact.

Tooling Impact

• [ ] Required tooling change
• [ ] Optional tooling change (include reasoning)

Customer Impact

• [ ] Customer reported
• [ ] Found internally

[Select one or both of the boxes. Describe how this issue impacts customers, citing the expected and actual behaviors and scope of the issue. If customer-reported, provide the issue number.]

Regression

• [ ] Yes
• [ ] No

[If yes, specify when the regression was introduced. Provide the PR or commit if known.]

Testing

[How was the fix verified? How was the issue missed previously? What tests were added?]

Risk

• [ ] High
• [ ] Medium
• [ ] Low

[High/Medium/Low. Justify the indication by mentioning how risks were measured and addressed.]