Merge branch 'mimemagic-git-shim' into 'master'

Don't use Git in the mimemagic shim

See merge request gitlab-org/gitlab!57516

vendor/shims/mimemagic/mimemagic.gemspec

@@ -12,10 +12,7 @@ Gem::Specification.new do |spec|
   spec.license       = "MIT"
   spec.required_ruby_version = Gem::Requirement.new(">= 2.3.0")
 
-  # Specify which files should be added to the gem when it is released.
-  # The `git ls-files -z` loads the files in the RubyGem that have been added into git.
-  spec.files         = Dir.chdir(File.expand_path('..', __FILE__)) do
-    `git ls-files -z`.split("\x0").reject { |f| f.match(%r{^(test|spec|features)/}) }
-  end
+  spec.files = %w[lib/mimemagic.rb lib/mimemagic/version.rb]
+
   spec.require_paths = ["lib"]
 end