Cleanup in preparation for #2500

[ycombinator]

What does this PR do?

This PR performs a bunch of cleanup, as suggested by golangci-lint.

Why is it important?

When #2500 was created, the golangci-lint linter made several suggestions in files touched by the PR, but not on lines related to the changes in that PR. This created unnecessary noise in the PR. To reduce that noise, I've extracted the changes to address those linter suggestions into this separate PR here.

Checklist

• My code follows the style guidelines of this project
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have made corresponding change to the default configuration files
• I have added tests that prove my fix is effective or that my feature works
• I have added an entry in ./changelog/fragments using the changelog tool
• I have added an integration test or an E2E test

[mergify]

This pull request does not have a backport label. Could you fix it @ycombinator? 🙏
To fixup this pull request, you need to add the backport labels for the needed
branches, such as:

• backport-v./d./d./d is the label to automatically backport to the 8./d branch. /d is the digit

NOTE: backport-skip has been added to this pull request.

[elasticmachine]

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• Start Time: 2023-04-18T19:13:13.689+0000

• Duration: 18 min 3 sec

Test stats 🧪

Test	Results
Failed	0
Passed	5535
Skipped	19
Total	5554

💚 Flaky test report

Tests succeeded.

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[elasticmachine]

🌐 Coverage report

Name	Metrics % (covered/total)	Diff
Packages	98.529% (67/68)	👍
Files	68.22% (161/236)	👍
Classes	67.785% (303/447)	👍
Methods	54.111% (928/1715)	👍
Lines	39.581% (10496/26518)	👎 -0.038
Conditionals	100.0% (0/0)	💚