Fix flaky test TestCommitStatusTargetURL

[hnnsgstfssn]

The test added in [1] uses environment variables in a parallel test which causes it to be flaky and sometimes fail as is described in [2].

To fix the flaky test, the environment variable is pulled out and read in the caller of the function under test, so that it can be tested without reading the global environment variable.

[1] a43d3d1
[2] https://pkg.go.dev/testing#T.Setenv

Type of Change

• Bug Fix
• New Feature
• Breaking Change
• Refactor
• Documentation
• Other (please describe)

Checklist

• I have read the contributing guidelines
• Existing issues have been referenced (where applicable)
• I have verified this change is not present in other open pull requests
• Functionality is documented
• All code style checks pass
• New code contribution is covered by automated tests
• All new and existing tests pass

[hnnsgstfssn]

Verified with

for i in $(seq 20); do go test ./... -count=1 -run=TestCommit; done