test: use T.TempDir to create temporary test directory

[Juneezee]

Description of the change:
A testing cleanup.

This pull request replaces ioutil.TempDir with t.TempDir. We can use the T.TempDir function from the testing package to create temporary directory. The directory created by T.TempDir is automatically removed when the test and all its subtests complete.

Reference: https://pkg.go.dev/testing#T.TempDir

func TestFoo(t *testing.T) {
	// before
	tmpDir, err := ioutil.TempDir("", "")
	if err != nil {
		t.Fatal(err)
	}
	defer os.RemoveAll(tmpDir)

	// now
	tmpDir := t.TempDir()
}

Motivation for the change:

This saves us at least 2 lines (error check, and cleanup) on every instance, or in some cases adds cleanup that we forgot.

Reviewer Checklist

• Implementation matches the proposed design, or proposal is updated to match implementation
• Sufficient unit test coverage
• Sufficient end-to-end test coverage
• Docs updated or added to /docs
• Commit messages sensible and descriptive

[openshift-ci]

Hi @Juneezee. Thanks for your PR.

I'm waiting for a operator-framework member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

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[timflannagan]

/ok-to-test

[codecov]

Codecov Report

Merging #1004 (703a2ab) into master (6ac352f) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #1004   +/-   ##
=======================================
  Coverage   52.87%   52.87%           
=======================================
  Files         104      104           
  Lines        9468     9468           
=======================================
  Hits         5006     5006           
  Misses       3529     3529           
  Partials      933      933           

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[timflannagan]

/lgtm

[dinhxuanvu]

/approve

[openshift-ci]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: dinhxuanvu, Juneezee

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