cherry-pick: persist-credentials false so LGTM token is used on push

actions/checkout defaults to persist-credentials: true, which leaves
an http.extraheader with the workflow's GITHUB_TOKEN in git config.
That overrides the LGTM token in the URL set by `git remote set-url`,
so `git push` fails with "Permission denied to github-actions[bot]"
when pushing the cherry-pick branch.

Author: tamalsaha

.github/workflows/cherry-pick.yml

@@ -13,6 +13,7 @@ jobs:
       - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
         with:
           fetch-depth: 0
+          persist-credentials: false
 
       - name: Generate LGTM App token
         id: lgtm-app-token