Chore: use new range for loops

[akagami-harsh]

Description

• Updates our codebase to use new integer range syntax for cleaner and more idiomatic loops. This replaces traditional counter loops for i := 0; i < n; i++ with the more concise for i := range n syntax where applicable. This change improves code readability while maintaining the same functionality.

Related Issue(s)

• Chore: use new range for loops #15193

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[vitess-bot]

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[vmg]

Personally I don't think these new for range loops on integers add to readability at all. I think they're a very weird inclusion to the language. I'd rather not rewrite the whole codebase to use them. @deepthi ?