Expand hostedtoolcache PATH integration for Python and other runtimes (#11979)

* Initial plan

* docs: initial plan for expanding hostedtoolcache PATH integration

Co-authored-by: Mossaka <5447827+Mossaka@users.noreply.github.com>

* feat: expand hostedtoolcache PATH integration for all runtimes

- Create shared GetHostedToolcachePathSetup() helper in engine_helpers.go
- Update claude_engine.go to use unified PATH setup (not just Node.js)
- Update codex_engine.go to use unified PATH setup (not just Node.js)
- Update copilot_engine_execution.go to use shared helper for consistency
- Add tests for GetHostedToolcachePathSetup in engine_helpers_test.go

The new PATH setup finds all bin directories in /opt/hostedtoolcache,
making Python, Go, Ruby, and other runtimes accessible in agent containers.

Fixes #12033

Co-authored-by: Mossaka <5447827+Mossaka@users.noreply.github.com>

* Regenerate lock files after merge with main

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: Mossaka <5447827+Mossaka@users.noreply.github.com>
Co-authored-by: Jiaxiao (mossaka) Zhou <duibao55328@gmail.com>
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

Author: 3 people