build(deps): Bump KSP to 2.3.7

KSP 2.1.0-1.0.29 is pinned to Kotlin compiler 2.1.0 and fails with
"ksp-2.1.0-1.0.29 is too old for kotlin-2.3.21" when the test matrix
runs the android-instrumentation-sample against newer Kotlin versions.
Bump to 2.3.7, which is the latest KSP2 release — KSP2 is decoupled
from the Kotlin compiler version and works across the Kotlin versions
the matrix now picks from developer.android.com/build/kotlin-support.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: romtsn

gradle/libs.versions.toml

@@ -17,7 +17,7 @@ kotlin = { id = "org.jetbrains.kotlin.jvm", version.ref = "kotlin" }
 kotlinAndroid = { id = "org.jetbrains.kotlin.android", version.ref = "kotlin" }
 kotlinSpring = { id = "org.jetbrains.kotlin.plugin.spring", version.ref = "kotlin" }
 kapt = { id = "org.jetbrains.kotlin.kapt", version.ref = "kotlin" }
-ksp = { id = "com.google.devtools.ksp", version = "2.1.0-1.0.29" }
+ksp = { id = "com.google.devtools.ksp", version = "2.3.7" }
 dokka = { id = "org.jetbrains.dokka", version = "1.9.20" }
 spotless = { id = "com.diffplug.spotless", version = "7.0.4" }
 groovyGradlePlugin = { id = "dev.gradleplugins.groovy-gradle-plugin", version = "1.7.1" }