build(deps): 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/maintenance-pr-listen-review.yml

@@ -13,7 +13,7 @@ jobs:
       - name: Save PR number
         run: echo "${{ github.event.pull_request.number }}" > pr.txt
 
-      - uses: actions/upload-artifact@v6
+      - uses: actions/upload-artifact@v7
         with:
           # unique name: includes workflow run id
           name: pr-number-${{ github.run_id }}

.github/workflows/maintenance-unit-tests.yml

@@ -151,7 +151,7 @@ jobs:
           echo "|${{ matrix.server.os }}| ${{ matrix.server.name }} | $((finish_time - start_time)) sec |" > ../test/${{ matrix.server.id }}-${{ matrix.server.os }}
 
       - name: "Upload test summary"
-        uses: actions/upload-artifact@v6
+        uses: actions/upload-artifact@v7
         with:
           name: test-${{ matrix.server.id }}-${{ matrix.server.os }}
           path: test