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/citation.yml

@@ -66,7 +66,7 @@ jobs:
           fi
       - name: Upload PDF
         if: always()
-        uses: actions/upload-artifact@v6
+        uses: actions/upload-artifact@v7
         with:
           name: citation-preview.pdf
           path: citation-preview.pdf

.github/workflows/docs.yml

@@ -49,7 +49,7 @@ jobs:
           cp -a docs/_build/html artifact/qiskit-paulice-htmldocs
       - name: Upload nice docs artifact
         if: always()
-        uses: actions/upload-artifact@v6
+        uses: actions/upload-artifact@v7
         with:
           name: qiskit-paulice-htmldocs
           path: ./artifact