Fix Gradle deprecation warnings and implicit dependency issues

[cbb330]

Summary

Fix Gradle deprecation warnings and implicit dependency issues to prepare for Gradle 8.0 compatibility.

This PR eliminates warnings that cause "Execution optimizations have been disabled" messages during builds, ensuring optimal build performance and future compatibility.

Build warnings fixed:

Warning	Status
JavaExec.main deprecated	✅ Fixed
mainClassName deprecated	✅ Fixed
Implicit dependency in dummytokens:jar	✅ Fixed
ConfigureUtil deprecated	⏳ Requires spotbugs plugin upgrade

Changes

• Client-facing API Changes
• Internal API Changes
• Bug Fixes
• New Features
• Performance Improvements
• Code Style
• Refactoring
• Documentation
• Tests

Bug Fixes

• Added explicit dependsOn configurations.runtimeClasspath to dummytokens:jar task to fix implicit dependency on configs:jar

Refactoring (Deprecation Fixes)

• Fixed deprecated mainClassName in scripts/java/tools/dummytokens/build.gradle → use application { mainClass = ... }
• Fixed deprecated JavaExec.main in integrations/spark/spark-3.1/openhouse-spark-runtime/build.gradle → use mainClass

Before (warnings during build):

Execution optimizations have been disabled for task ':scripts:java:tools:dummytokens:jar' 
to ensure correctness due to the following reasons:
- Task ':scripts:java:tools:dummytokens:jar' uses output of task ':cluster:configs:jar' 
  without declaring an explicit or implicit dependency.

The JavaExec.main property has been deprecated. This is scheduled to be removed in Gradle 8.0.

After (no warnings):

BUILD SUCCESSFUL in 5m 34s
254 actionable tasks: 244 executed, 10 up-to-date

Testing Done

• Manually Tested on local docker setup. Please include commands ran, and their output.
• Added new tests for the changes made.
• Updated existing tests to reflect the changes made.
• No tests added or updated. Please explain why. If unsure, please feel free to ask for help.
• Some other form of testing like staging or soak time in production. Please explain.

Manual Testing

1. Ran ./gradlew clean build -x test --warning-mode all
2. Verified implicit dependency warning is gone
3. Verified JavaExec.main deprecation warning is gone

No Tests Added

This is a build infrastructure change that doesn't affect runtime behavior.

Additional Information

• Breaking Changes
• Deprecations
• Large PR broken into smaller PRs, and PR plan linked in the description.

🤖 Generated with Claude Code

[cbb330]

Closing - these are cosmetic deprecation warning fixes with no tangible benefit.