Bump actions/upload-artifact from 3 to 4

Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from 3 to 4.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](actions/upload-artifact@v3...v4)

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

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

.github/workflows/ci.yaml

@@ -73,7 +73,7 @@ jobs:
 
       - name: Archive code coverage results
         if: ${{matrix.python-version == '3.9'}}
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: code-coverage-report
           path: .coverage

.github/workflows/spec_tests.yaml

@@ -44,13 +44,13 @@ jobs:
            python -m unittest spec_tests/validate_bids.py > validate_bids_results.txt
 
       - name: Upload error test results
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: error-test-results
           path: error_results.txt
 
       - name: Upload bids test results
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: bids-test-results
           path: validate_bids_results.txt