github: Reenable Gemini, but no auto code review

Author: bep

.gemini/config.yaml

@@ -2,12 +2,12 @@ have_fun: false
 memory_config:
   disabled: false
 code_review:
-  disable: true
+  disable: false
   comment_severity_threshold: HIGH
   max_review_comments: -1
   pull_request_opened:
-    help: false
-    summary: true
-    code_review: true
+    help: true
+    summary: false
+    code_review: false
     include_drafts: false
 ignore_patterns: []