Update android.gradle.plugin to v9

Author: renovate[bot]

gradle/libs.versions.toml

@@ -1,6 +1,6 @@
 [versions]
 accompanist = "0.36.0"
-android-gradle-plugin = "8.13.2"
+android-gradle-plugin = "9.1.1"
 androidx-activity = "1.13.0"
 androidx-compose-foundation = "1.10.6"
 androidx-compose-material3 = "1.4.0"