chore: Update actions/create-github-app-token digest to 21cfef2

Author: grafanarenovatebot[bot]

.github/workflows/release-please.yml

@@ -32,7 +32,7 @@ jobs:
 
       - name: Generate a token
         id: generate-token
-        uses: actions/create-github-app-token@0d564482f06ca65fa9e77e2510873638c82206f2 # v1
+        uses: actions/create-github-app-token@21cfef2b496dd8ef5b904c159339626a10ad380e # v1
         with:
           app-id: ${{ env.GITHUB_APP_ID }}
           private-key: ${{ env.GITHUB_APP_PRIVATE_KEY }}