Use Prom-Op bot PAT token in dependabot workflow (#6128)

Signed-off-by: Arthur Silva Sens <arthur.sens@coralogix.com>

.github/workflows/automerge-dependabot.yaml

@@ -19,15 +19,16 @@ jobs:
         if: contains(steps.metadata.outputs.dependency-names, 'k8s.io/api')
         uses: actions/checkout@v4
         with:
-          token: ${{ secrets.GITHUB_TOKEN }}
+          token: ${{ secrets.PROM_OP_BOT_PAT }}
           ref: ${{ github.event.pull_request.head.ref }}
       - name: Generate Documentation/compatibility.md
         if: contains(steps.metadata.outputs.dependency-names, 'k8s.io/api')
         run: |
+          export GITHUB_TOKEN="${{ secrets.PROM_OP_BOT_PAT }}"
           make generate --always-make
           if ! git diff --exit-code; then
-            git config --global user.email "support@github.com"
-            git config --global user.name "dependabot[bot]"
+            git config --global user.email "prom-op-bot@users.noreply.github.com"
+            git config --global user.name "Prometheus Operator Bot"
             git add Documentation/compatibility.md
             git commit -s -m "Generate Documentation/compatibility.md"
             git push