ci: bump actions/upload-artifact from 4 to 6 in the actions group (#162)

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/maxwell2d-lumerical.yml

@@ -92,7 +92,7 @@ jobs:
 
       - name: (DOCS) Upload docs artifacts
         if: needs.is-only-docs-required.outputs.only-docs == 'true' && matrix.ansys-release == env.ANSYS_RELEASE_FOR_DOCS
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         with:
           name: maxwell2d-lumerical-docs
           path: |