🧹 [code health improvement] Remove unnecessary clones in stdlib module registration

[Tcode-Motion]

🎯 What: Removed unnecessary .clone() calls on the exports map when registering std.fs and std.hex modules in the standard library.
💡 Why: The exports map was being cloned just before being moved into the StdlibModule struct, but it was never used again afterwards. Removing the clone improves performance slightly and reduces memory overhead by transferring ownership directly.
✅ Verification: Ran cargo test --workspace to ensure no functionality is broken, and cargo clippy and cargo fmt to verify code format and lints.
✨ Result: Cleaner code and fewer unnecessary heap allocations during VM startup.

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PR created automatically by Jules for task 1598574747614381823 started by @Tcode-Motion

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