ko: replace `git` with `gitMinimal`

pkgs/by-name/ko/ko/package.nix

···
   lib,
   buildGoModule,
   fetchFromGitHub,
-  git,
+  gitMinimal,
   installShellFiles,
 }:
 
···
     "-skip=TestNewPublisherCanPublish"
   ];
 
-  nativeCheckInputs = [ git ];
+  nativeCheckInputs = [ gitMinimal ];
   preCheck = ''
     # Feed in all the tests for testing
     # This is because subPackages above limits what is built to just what we