[K/N][test] Increase default test timeout to 30 seconds

Sometimes on slower hosts longer running test may time out.

Merge-request: KT-MR-9935
Merged-by: Pavel Punegov <Pavel.Punegov@jetbrains.com>

native/native.tests/tests/org/jetbrains/kotlin/konan/blackboxtest/support/settings/TestProcessSettings.kt

@@ -181,7 +181,7 @@ internal class BaseDirs(val testBuildDir: File)
  */
 internal class Timeouts(val executionTimeout: Duration) {
     companion object {
-        val DEFAULT_EXECUTION_TIMEOUT: Duration get() = 15.seconds
+        val DEFAULT_EXECUTION_TIMEOUT: Duration get() = 30.seconds
     }
 }