chore(deps): bump actions/upload-artifact from 5 to 6

Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from 5 to 6.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](actions/upload-artifact@v5...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] <support@github.com>

Author: dependabot[bot]

.github/workflows/check-urls.yml

@@ -107,7 +107,7 @@ jobs:
         if: ${{ endsWith(matrix.file, '.yml') || endsWith(matrix.file, '.md') }}
         run: |
           awesome_bot "${{ matrix.file }}" --allow-redirect --allow-dupe --allow-ssl || true;
-      - uses: actions/upload-artifact@v5
+      - uses: actions/upload-artifact@v6
         with:
           name: ${{ steps.set-output.outputs.FILEPATH }}
           path: ${{ github.workspace }}/ab-results-*.json

.github/workflows/fpb-lint.yml

@@ -29,7 +29,7 @@ jobs:
           echo ${{ github.event.pull_request.html_url }} > ./pr/PRurl
           cat output.log | sed -E 's:/home/runner/work/free-programming-books/|⚠.+::' | uniq > ./pr/error.log
 
-    - uses: actions/upload-artifact@v5
+    - uses: actions/upload-artifact@v6
       if: always()
       with:
         name: pr

.github/workflows/rtl-ltr-linter.yml

@@ -94,7 +94,7 @@ jobs:
     # Only if the linter step was executed (success or failure)
     - name: Upload linter output artifact
       if: steps.run_linter.conclusion == 'success' || steps.run_linter.conclusion == 'failure'
-      uses: actions/upload-artifact@v5
+      uses: actions/upload-artifact@v6
       with:
         name: rtl-linter-output # Name of the artifact
         path: rtl-linter-output.log # Path to the output file