Replace vet with golangci lint govet

[alessio]

Fix inconsistencies and small mistakes as per golangci-lint run's report.

Upgrade golangci-lint to 1.16.0.

• Linked to github-issue with discussion and accepted design OR link to spec that describes this work.
• Wrote tests
• Updated relevant documentation (docs/)
• Added a relevant changelog entry: clog add [section] [stanza] [message]
• rereviewed Files changed in the github PR explorer

---

For Admin Use:

• Added appropriate labels to PR (ex. wip, ready-for-review, docs)
• Reviewers Assigned
• Squashed all commits, uses message "Merge pull request #XYZ: [title]" (coding standards)

[codecov]

Codecov Report

Merging #4277 into master will decrease coverage by 0.01%.
The diff coverage is 0%.

@@            Coverage Diff            @@
##           master   #4277      +/-   ##
=========================================
- Coverage   59.12%   59.1%   -0.02%     
=========================================
  Files         217     217              
  Lines       14595   14595              
=========================================
- Hits         8629    8627       -2     
- Misses       5328    5330       +2     
  Partials      638     638

[codecov]

Codecov Report

Merging #4277 into master will decrease coverage by 0.01%.
The diff coverage is 0%.

@@            Coverage Diff            @@
##           master   #4277      +/-   ##
=========================================
- Coverage   59.12%   59.1%   -0.02%     
=========================================
  Files         217     217              
  Lines       14595   14595              
=========================================
- Hits         8629    8627       -2     
- Misses       5328    5330       +2     
  Partials      638     638

[sabau]

👍 nice cleanup