NIT: Remove unused param (#6446)

openhands/resolver/resolve_issue.py

@@ -567,12 +567,6 @@ def main():
         choices=['issue', 'pr'],
         help='Type of issue to resolve, either open issue or pr comments.',
     )
-    parser.add_argument(
-        '--target-branch',
-        type=str,
-        default=None,
-        help="Target branch to pull and create PR against (for PRs). If not specified, uses the PR's base branch.",
-    )
     parser.add_argument(
         '--is-experimental',
         type=lambda x: x.lower() == 'true',