perf: reduce allocation for adding dependencies

[h-a-n-a]

Summary

(Also the heavy computation)

Dependency paths returned from oxc-resolver had already been normalized.
See: https://github.com/oxc-project/oxc-resolver/blob/f4c3ef5b4765ec8fcfb0f0d74a7562a6baa1456c/src/lib.rs#L380

Reduced memory cost by about 28.7% (at peak) for the case of 10000 modules (Rspack was compiled with debug profile).

Before:

After:

Checklist

• Tests updated (or not required).
• Documentation updated (or not required).

[h-a-n-a]

!bench

[rspack-bot]

📝 Benchmark detail: Open

Name	Base (2024-07-24 5392167)	Current	Change
10000_development-mode + exec	2.26 s ± 28 ms	2.21 s ± 31 ms	-2.30 %
10000_development-mode_hmr + exec	691 ms ± 6.4 ms	696 ms ± 8.3 ms	+0.65 %
10000_production-mode + exec	2.87 s ± 22 ms	2.78 s ± 28 ms	-3.24 %
arco-pro_development-mode + exec	1.93 s ± 62 ms	1.9 s ± 78 ms	-1.69 %
arco-pro_development-mode_hmr + exec	433 ms ± 1.7 ms	433 ms ± 1.2 ms	+0.06 %
arco-pro_production-mode + exec	3.5 s ± 66 ms	3.42 s ± 69 ms	-2.39 %
threejs_development-mode_10x + exec	1.75 s ± 23 ms	1.75 s ± 19 ms	-0.25 %
threejs_development-mode_10x_hmr + exec	856 ms ± 5.1 ms	856 ms ± 4.3 ms	-0.06 %
threejs_production-mode_10x + exec	5.74 s ± 44 ms	5.72 s ± 28 ms	-0.24 %