GH-1699 - Add Gradle build resources to JUnit change detection

[char-yb]

Adds additional Gradle build resources to the JUnit change detection fallback used by Change-Aware Test Execution.

Changes to build configuration, build metadata, or custom build logic can affect test execution even when no application source file changed. The current detection already backs off for selected build files. This PR broadens that detection to cover common Gradle build resources more consistently.

Key changes:

• Add internal BuildResourceChangeDetector for build-resource path matching
• Detect Gradle scripts, version catalogs, wrapper configuration, buildSrc, and build-logic changes
• Keep application Kotlin source files classified as source changes
• Document the broader Gradle build-resource fallback behavior

The detection remains version-agnostic by matching repository-relative file roles instead of Kotlin or Gradle version strings.