Performance: Replace `fold` with `find_map` in locator identification loop

[karthiknadig]

Summary

The locator identification loop in locators.rs uses a fold pattern that continues iterating through all locators even after a match is found. This is inefficient and should be replaced with find_map which short-circuits on the first match.

Current Implementation

File: crates/pet/src/locators.rs (lines 106-109 and 120-123)

if let Some(env) = locators.iter().fold(
    None,
    |e, loc| if e.is_some() { e } else { loc.try_from(env) },
) {
    return Some(env);
}

Proposed Change

if let Some(env) = locators.iter().find_map(|loc| loc.try_from(env)) {
    return Some(env);
}

Impact

• CPU savings: Avoids unnecessary iterations after a match is found
• Cleaner code: find_map is more idiomatic for this use case
• Both occurrences in identify_python_environment_using_locators should be updated

Priority

High - This is called frequently during environment discovery and is an easy win.