Bump org.jetbrains.intellij.platform:intellij-platform-gradle-plugin (ChrisCarini/github-repo-files-sync#290)

Bumps [org.jetbrains.intellij.platform:intellij-platform-gradle-plugin](https://github.com/JetBrains/intellij-platform-gradle-plugin) from 2.8.0 to 2.9.0.
- [Release notes](https://github.com/JetBrains/intellij-platform-gradle-plugin/releases)
- [Commits](JetBrains/intellij-platform-gradle-plugin@2.8.0...2.9.0)

---
updated-dependencies:
- dependency-name: org.jetbrains.intellij.platform:intellij-platform-gradle-plugin
  dependency-version: 2.9.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: ChrisCarini

buildSrc/build.gradle.kts

@@ -10,7 +10,7 @@ repositories {
 }
 
 dependencies {
-    implementation("org.jetbrains.intellij.platform:intellij-platform-gradle-plugin:2.8.0")
+    implementation("org.jetbrains.intellij.platform:intellij-platform-gradle-plugin:2.9.0")
     implementation("org.jetbrains.intellij.plugins:gradle-changelog-plugin:2.4.0")
     implementation("com.dorongold.plugins:task-tree:4.0.1") // provides `taskTree` task (e.g. `./gradlew build taskTree`; docs: https://github.com/dorongold/gradle-task-tree)
 }