Simplify PR Review Prompt

[jerop]

The current Gemini PR review workflow prompt is excessively verbose (~300+ lines). This makes it challenging for users to configure it to fit their needs, and likely increase token consumption.

We want to simplify the prompt while preserving essential functionality and formatting guidance.

cc @anj-s

[dan-ri]

I have done this in the course of resolving several critical issues related to tool calling and line number and side handling.

[jerop]

I have done this in the course of resolving several critical issues related to tool calling and line number and side handling.

@dan-ri would appreciate any feedback from your experiences - #209