Fix golang-ci lint configuration exclude configuration

[sbueringer]

The exclude configuration Using the variable on range scope (tc)|(rt)|(tt)|(test)|(testcase)|(testCase) in function literal in .golang.ci.yml matches too many findings.

Every finding which contains "rt", "tt", "test", .. is excluded.

For more context:

• Fix PR in cluster-api
• Follow-up PR for migration doc
• Discussion in Slack

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/lifecycle stale

[timoreimann]

/remove-lifecycle stale

[cpanato]

did not see this issue, will work on that

/assign