chore(deps): update amannn/action-semantic-pull-request action to v6

Author: unity-renovate[bot]

.github/workflows/conventional-pr.yml

@@ -17,7 +17,7 @@ jobs:
     steps:
       - name: semantic-pull-request
         # Internal Unity mirror available at jesseo/action-semantic-pull-request, but actions from private repos aren't supported, so continue to use the public one below
-        uses: amannn/action-semantic-pull-request@v5
+        uses: amannn/action-semantic-pull-request@v6
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         with: