fix: Remove RandomXBenchmark.java to fix compilation errors

The RandomXBenchmark.java file conflicts with the Benchmark.java class
and causes JMH annotation compilation errors.

Keeping only Benchmark.java which provides command-line benchmark
functionality compatible with the C++ benchmark format.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: LucasMLK