Remove GitHub build exclusions

[bbonaby]

📖 Description

We currently exclude .md files from the Build workflow here:

mxc/.github/workflows/Build.yml

Line 19 in b19e812

paths-ignore:

However, in the repository settings, the GitHub Actions checks are marked as required. As a result, when a PR only changes .md files, such as #539, the Build workflow does not run because those files are excluded. Since the required check is never produced, GitHub blocks the PR from merging due to a missing required status check. This change now removes the excludes. We will now run the pipeline for all PRs so we can keep the pipelines as required.

🔗 References

🔍 Validation

✅ Checklist

• Signed the Contributor License Agreement
• Linked to an issue
• Updated documentation (if applicable)
• Updated Copilot instructions (if build, architecture, or conventions changed)

📋 Issue Type

• Bug fix
• Feature
• Task

---

GitHub Actions runs the PR validation build automatically. The ADO pipeline
(MXC-PR-Build) is the official build pipeline that signs the binaries; it
runs on merge to main and nightly, and Microsoft reviewers can trigger it
on a PR with /azp run. See docs/pull-requests.md.

Microsoft Reviewers: Open in CodeFlow

[Copilot]

Pull request overview

Removes paths-ignore filters from the GitHub Actions Build workflow so that the required Build check is always generated, even for PRs that only change documentation/markdown or repo metadata files.

Changes:

• Removed paths-ignore for pull_request so docs-only PRs still trigger the Build workflow (avoids “missing required status check” merge blocks).
• Removed paths-ignore for push to main so the workflow runs for all pushes as well.