fix: use CUSTOM_GITHUB_TOKEN for checkout and rebase before push in create-issues workflow

Agent-Logs-Url: https://github.com/pmcelhaney/counterfact/sessions/1107a431-bdb2-40bb-b345-72ef9c287f3c

Co-authored-by: pmcelhaney <51504+pmcelhaney@users.noreply.github.com>

Author: Copilot

.github/workflows/create-issues.yml

@@ -17,6 +17,8 @@ jobs:
     steps:
       - name: Check out repository
         uses: actions/checkout@v6
+        with:
+          token: ${{ secrets.CUSTOM_GITHUB_TOKEN }}
 
       - name: Install Python dependencies
         run: pip install pyyaml
@@ -37,5 +39,6 @@ jobs:
             echo "No proposal files were deleted — nothing to commit."
           else
             git commit -m "chore: remove processed issue proposals"
+            git pull --rebase
             git push
           fi