refactor: remove redundant variable declarations in for loops

[efcking]

Summary

The new version of Go has been optimized, and variables do not need to be reassigned.

For more info: https://tip.golang.org/wiki/LoopvarExperiment#does-this-mean-i-dont-have-to-write-x--x-in-my-loops-anymore

Changes

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Testing

Steps

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Results

Regressions

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Notes for Reviewers

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Checklist

• Scope: The referenced issue is addressed, there are no unrelated changes.
• Compatibility: The changes are backwards compatible with existing API, storage, configuration and CLI, according to the compatibility commitments in README.md for the chosen target branch.
• Documentation: Relevant documentation is added or updated.
• Testing: The steps/process to test this feature are clearly explained including testing for regressions.
• Infrastructure: If infrastructural changes (e.g., new RPC, configuration) are needed, a separate issue is created in the infrastructural repositories.
• Changelog: Significant features, behavior changes, deprecations and fixes are added to CHANGELOG.md.
• Commits: Commit messages follow guidelines in CONTRIBUTING.md, there are no fixup commits left.

[efcking]

There seem to be a lot of changes. Do I need to split them into multiple PRs to submit?

[johanstokking]

Thanks, I hope you did this with a regex replace 😁

One small comment.

[nicholaspcr]

This looks really nice, appreciate the contribution.