Merge branch 'remove-duplicate-prepend-deprecated-mutation' into 'master'

Remove duplicated prepend of `EE::Types::DeprecatedMutations`

See merge request gitlab-org/gitlab!52066

app/graphql/types/mutation_type.rb

@@ -98,5 +98,4 @@ module Types
 end
 
 ::Types::MutationType.prepend(::Types::DeprecatedMutations)
-::Types::MutationType.prepend_if_ee('EE::Types::DeprecatedMutations')
 ::Types::MutationType.prepend_if_ee('::EE::Types::MutationType')