refactor(genetic_algorithm): optimize evaluate function using zip

[loulanyue]

Summary

In genetic_algorithm/basic_string.py:

• evaluate previously constructed a list with [g for position, g in enumerate(item) if g == main_target[position]] and took len(...).
• If item and main_target have mismatched lengths, indexing main_target[position] can raise IndexError.
• This PR replaces list comprehension with sum(1 for g, t in zip(item, main_target) if g == t) which is safer, more Pythonic, and avoids intermediate list allocation.

[algorithms-keeper]

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