Excavator: Update Gradle Test Versions (#1332)

Author: svc-excavator-bot

gradle-palantir-java-format/build.gradle

@@ -115,5 +115,5 @@ tasks.named("test").configure {
 }
 
 gradleTestUtils {
-    gradleVersions = ['7.6.5', '8.14.2']
+    gradleVersions = ['8.14.2']
 }