Remove GitKracken files from GitIgnore (PowerShell#8743)

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## PR Summary
GitKracken now automatically prevents them from being committed, so this is not needed.  
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Author: RDIL

.gitignore

@@ -83,9 +83,5 @@ PowerShell.sln.DotSettings.user
 *.msp
 StyleCop.Cache
 
-# GitKracken Files
-.gk/
-gkconfig.yml
-
 # Ignore SelfSignedCertificate autogenerated files
 test/tools/Modules/SelfSignedCertificate/