chore(deps): bump actions/upload-artifact from 4 to 6

Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from 4 to 6.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](actions/upload-artifact@v4...v6)

---
updated-dependencies:
- dependency-name: actions/upload-artifact
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

.github/workflows/generate_coverage_pr.yaml

@@ -66,13 +66,13 @@ jobs:
       # Triggered sub-workflow is not able to detect the original commit/PR which is available
       # in this workflow.
       - name: Store PR number
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         with:
           name: pr_number
           path: pr_number.txt
 
       - name: Store commit SHA
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         with:
           name: commit_sha
           path: commit_sha.txt
@@ -81,7 +81,7 @@ jobs:
       # is executed by a different workflow `coverage-report.yml`. The reason for this
       # split is because `on.pull_request` workflows don't have access to secrets.
       - name: Store coverage report in artifacts
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         with:
           name: codecov_report
           path: ./lcov.info