refactor: improve error handling and optimize memory allocation

[reject-i]

Motivation

This PR improves error handling and memory allocation in two key areas:

1. The parse_rustc_version function currently uses expect() which can cause panics with unclear error messages when encountering unexpected rustc version formats. This makes debugging difficult and reduces reliability.

2. The chunk_vec function creates unnecessary memory allocations when processing large vectors, which can impact performance in memory-intensive operations.

Solution

1. Enhanced parse_rustc_version to return a proper Result type instead of using expect(), providing more informative error messages and allowing callers to handle errors gracefully.

2. Optimized chunk_vec with pre-allocation strategies:

   • Pre-allocating the result vector with the correct capacity
   • Pre-allocating each chunk with its exact size
   • Using extend instead of collect to avoid intermediate allocations

PR Checklist

• Added Tests
• Added Documentation
• Breaking changes