fix: disable noisy gemini summary (#2524)

Co-authored-by: Håkon V. Treider <haakonvt@gmail.com>

Author: trygveu

.gemini/config.yaml

@@ -5,7 +5,7 @@ code_review:
   max_review_comments: -1
   pull_request_opened:
     help: false
-    summary: true
+    summary: false
     code_review: true
     include_drafts: false
 ignore_patterns: []