ci: auto-merge patch updates as well as minor

Patch updates are the safest update class but were queuing for manual
merge under the minor-only automerge rule. Extend the Renovate
automerge rule to patch + minor (on stable maintenance branches patch
is the only allowed update type, so those PRs now automerge too).
CI remains the gate: Renovate only merges when checks are green.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: emilyoram

.github/renovate.json

@@ -25,8 +25,8 @@
       "enabled": false
     },
     {
-      "description": "Auto-merge minor updates once CI is green.",
-      "matchUpdateTypes": ["minor"],
+      "description": "Auto-merge minor and patch updates once CI is green.",
+      "matchUpdateTypes": ["minor", "patch"],
       "automerge": true
     }
   ],