Bump microsoft/PR-Metrics from 1.7.14 to 1.7.15 (#862)

Bumps [microsoft/PR-Metrics](https://github.com/microsoft/pr-metrics) from 1.7.14 to 1.7.15.
- [Release notes](https://github.com/microsoft/pr-metrics/releases)
- [Commits](microsoft/PR-Metrics@v1.7.14...v1.7.15)

---
updated-dependencies:
- dependency-name: microsoft/PR-Metrics
  dependency-version: 1.7.15
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/build.yml

@@ -25,7 +25,7 @@ jobs:
       with:
         fetch-depth: 0
     - name: PR Metrics
-      uses: microsoft/PR-Metrics@v1.7.14
+      uses: microsoft/PR-Metrics@v1.7.15
       env:
         PR_METRICS_ACCESS_TOKEN: ${{ secrets.GITHUB_TOKEN }}