Bump actions/upload-artifact from 6 to 7

Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from 6 to 7.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](actions/upload-artifact@v6...v7)

---
updated-dependencies:
- dependency-name: actions/upload-artifact
  dependency-version: '7'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/coverage.yml

@@ -62,7 +62,7 @@ jobs:
 
       - name: Upload test results
         if: failure()
-        uses: actions/upload-artifact@v6
+        uses: actions/upload-artifact@v7
         with:
           name: coverage-test-failures
           path: ${{ runner.temp }}/package

.github/workflows/rcmdcheck.yml

@@ -78,7 +78,7 @@ jobs:
         id: rcmdcheck
         run: |
           Rscript -e "rcmdcheck::rcmdcheck(args = c('--as-cran', '--no-manual'), error_on = 'warning')"
-      - uses: actions/upload-artifact@v6
+      - uses: actions/upload-artifact@v7
         if: failure()
         with:
           name: ${{ runner.os }}-log