Update upload-artifact to 6.0.0

Issue gh-18648

Signed-off-by: Josh Cummings <3627351+jzheaux@users.noreply.github.com>

Author: jzheaux

.github/workflows/pr-build-workflow.yml

@@ -34,7 +34,7 @@ jobs:
         run: ./gradlew -PbuildSrc.skipTests=true :spring-security-docs:antora
       - name: Upload Docs
         id: upload
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@b7c566a772e6b6bfb58ed0dc250532a479d7789f # v6.0.0
         with:
           name: docs
           path: docs/build/site