chore(deps): update fluxcd/flux2 action to v2.8.1

Author: renovate[bot]

.github/workflows/publish-kustomize-bundle.yaml

@@ -60,7 +60,7 @@ jobs:
           password: ${{ secrets.GITHUB_TOKEN }}
 
       - name: Setup Flux CLI
-        uses: fluxcd/flux2/action@v2.7.5
+        uses: fluxcd/flux2/action@v2.8.1
 
       - name: Install Kustomize
         run: |