[lang] Update minimum requirement for CMAKE

[linull24]

Issue: #8673

Brief Summary

copilot:summary
This PR resolves CMake 4.0 compilation failures by standardizing the minimum required version to 3.17 across all submodules (TaichiExamples/TaichiCAPITests/TaichiCAPI/TaichiTests), ensuring compatibility with modern Linux distributions.

Walkthrough

copilot:walkthrough

Context

• CMake 4.0 dropped legacy support (including CMake 3.5) causing build failures on updated distros
• Reference: CMake Version Policy

Changes Made

1. Updated version requirement in:
   • TaichiExamples.cmake
   • TaichiCAPITests.cmake
   • TaichiCAPI.cmake
   • TaichiTests.cmake
2. Unified requirement to CMake 3.17 (already the de facto standard)

Impact Analysis

• No breaking changes (3.17 was already the effective minimum)
• Improves forward compatibility
• Affects only build system configuration

Verification

• No new tests needed (version requirement change only)
• Confirmed via manual build testing

Additional Notes

• Aligns with CMake's modern version policy
• Prevents future issues on rolling-release distros
• Maintains backward compatibility

I sincerely apologize for the additional PR noise (#8701, #8678). Due to my initial lack of Git proficiency, I inadvertently created redundant PRs while attempting to sync with upstream. This new PR (#8702) consolidates all changes with proper rebasing.

Thank you for your patience, and I appreciate your guidance throughout this process.