Pin Gradle to <9.4 (incompatible with React Native 0.85.3) (#37)

Gradle >=9.4 bundles a Kotlin 2.3.x stdlib, but RN 0.85.3's bundled
gradle-plugin is compiled with Kotlin 2.1.20, which cannot read Kotlin 2.3
metadata — the build fails compiling the RN settings-plugin. 9.3.1 (Kotlin
2.2.21) is the highest working version. Stops Renovate from re-proposing the
broken upgrade (PR #34) until React Native ships a plugin built with newer
Kotlin.

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: dfalling

renovate.json

@@ -2,6 +2,12 @@
   "$schema": "https://docs.renovatebot.com/renovate-schema.json",
   "extends": ["config:recommended"],
   "packageRules": [
+    {
+      "description": "Pin Gradle to <9.4. React Native 0.85.3's bundled gradle-plugin (node_modules/@react-native/gradle-plugin) is compiled with Kotlin 2.1.20, whose compiler can only read Kotlin metadata up to 2.3. Gradle >=9.4 bundles a Kotlin 2.3.x stdlib (metadata 2.3.0) that leaks onto the settings-plugin compile classpath, so the build fails compiling the RN plugin (`Module was compiled with an incompatible version of Kotlin`). 9.3.1 (Kotlin 2.2.21) is the highest working version. Raise this ceiling once React Native ships a gradle-plugin built with Kotlin >=2.3.",
+      "matchPackageNames": ["gradle"],
+      "matchManagers": ["gradle-wrapper"],
+      "allowedVersions": "<9.4.0"
+    },
     {
       "description": "Group the React Native core and its tooling — they are pinned to the same release and must bump atomically",
       "matchPackageNames": [