[pigeon]: Bump kotlin-gradle-plugin (#3015)

Bumps [kotlin-gradle-plugin](https://github.com/JetBrains/kotlin) from 1.7.22 to 1.8.0.
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/master/ChangeLog.md)
- [Commits](JetBrains/kotlin@v1.7.22...v1.8.0)

---
updated-dependencies:
- dependency-name: org.jetbrains.kotlin:kotlin-gradle-plugin
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

packages/pigeon/platform_tests/test_plugin/android/build.gradle

@@ -2,7 +2,7 @@ group 'com.example.test_plugin'
 version '1.0-SNAPSHOT'
 
 buildscript {
-    ext.kotlin_version = '1.7.22'
+    ext.kotlin_version = '1.8.0'
     repositories {
         google()
         mavenCentral()