Enable ginkgolinter and fix finding

[nunnatsa]

Proposed changes

Enable ginkgolinter in .golangci.yaml, and fix its findings.

The fixing was done by running the ginkgolinter cli. All the finding except for one, are categorized as style findings, e.g. Expect(err).To(BeNil()) instead of Expect(err).ToNot(HaveOccurred()).

The linter also found one real issue in tests/suite/longevity_test.go, where there was a check (Expect) with no assertion (To(...)). That was fixed manually from:

Expect(framework.WriteContent(resultsFile, "\n## Traffic\n"))

to

Expect(framework.WriteContent(resultsFile, "\n## Traffic\n")).To(Succeed())

Closes #1678

Checklist

• I have read the CONTRIBUTING doc
• I have added tests that prove my fix is effective or that my feature works
• I have checked that all unit tests pass after adding my changes
• I have updated necessary documentation
• I have rebased my branch onto main
• I will ensure my PR is targeting the main branch and pulling from my branch from my own fork

Release notes

None

[sjberman]

Thanks for the contribution!

[kate-osborn]

@nunnatsa, thanks for adding this! This will be very helpful 😄

[nunnatsa]

@kate-osborn and @sjberman, thanks for the review. Fixed. PTAL.

BTW, the next version of the ginkgolinter will include an option to force Expect().To()/ToNot() + otiopn to auto fix Expect().Should()/ShouldNot().