Enable draft_pr config for backport pr's (#45778)

.cherry_picker.toml

@@ -21,3 +21,4 @@ repo = "airflow"
 fix_commit_msg = false
 default_branch = "main"
 require_version_in_branch_name=false
+draft_pr = true

.github/workflows/backport-cli.yml

@@ -61,7 +61,7 @@ jobs:
       - name: Install Python dependencies
         run: |
           python -m pip install --upgrade pip
-          python -m pip install cherry-picker==2.4.0 requests==2.32.3
+          python -m pip install cherry-picker==2.5.0 requests==2.32.3
 
       - name: Run backport script
         id: execute-backport