Remove all code related to generic_class Sorbet flag

Since sorbet/sorbet#6781 was merged and released as 0.5.10820, we no longer need to check for the existence of generic class support in Sorbet. Since we are moving to >= 0.5.10820, we can remove all code related to the `generic_class` flag.

Author: paracycle

lib/tapioca/dsl/compilers/active_record_delegated_types.rb

@@ -110,11 +110,10 @@ def populate_role_accessors(mod, role, types)
             return_type: "ActiveSupport::StringInquirer",
           )
 
-          return_type = sorbet_supports?(:generic_class) ? "T::Class[T.anything]" : "Class"
           mod.create_method(
             "#{role}_class",
             parameters: [],
-            return_type: return_type,
+            return_type: "T::Class[T.anything]",
           )
 
           mod.create_method(

lib/tapioca/helpers/sorbet_helper.rb

@@ -24,7 +24,6 @@ module SorbetHelper
     FEATURE_REQUIREMENTS = T.let(
       {
         # feature_name: ::Gem::Requirement.new(">= ___"), # https://github.com/sorbet/sorbet/pull/___
-        generic_class: ::Gem::Requirement.new(">= 0.5.10820"), # https://github.com/sorbet/sorbet/pull/6781
       }.freeze,
       T::Hash[Symbol, ::Gem::Requirement],
     )

spec/tapioca/cli/backwards_compatibility_spec.rb

@@ -27,68 +27,6 @@ def foo(foo)
       @project.destroy!
     end
 
-    describe "serialization of T::Class and T.anything" do
-      before do
-        foo = mock_gem("foo", "0.0.1") do
-          write!("lib/foo.rb", <<~RB)
-            Foo = T.type_alias { T.any(T.anything, T::Class[String]) }
-          RB
-        end
-        @project.require_mock_gem(foo)
-      end
-
-      it "serializes both as untyped with Sorbet < 0.5.10782" do
-        @project.require_real_gem("sorbet-static", "0.5.10780")
-        @project.bundle_install!
-
-        @project.tapioca("gem foo")
-
-        assert_project_file_equal("sorbet/rbi/gems/foo@0.0.1.rbi", <<~RBI)
-          # typed: true
-
-          # DO NOT EDIT MANUALLY
-          # This is an autogenerated file for types exported from the `foo` gem.
-          # Please instead update this file by running `bin/tapioca gem foo`.
-
-          Foo = T.type_alias { T.untyped }
-        RBI
-      end
-
-      it "serializes T::Class as untyped with Sorbet >= 0.5.10782 and < 0.5.10820" do
-        @project.require_real_gem("sorbet-static", "0.5.10800")
-        @project.bundle_install!
-
-        @project.tapioca("gem foo")
-
-        assert_project_file_equal("sorbet/rbi/gems/foo@0.0.1.rbi", <<~RBI)
-          # typed: true
-
-          # DO NOT EDIT MANUALLY
-          # This is an autogenerated file for types exported from the `foo` gem.
-          # Please instead update this file by running `bin/tapioca gem foo`.
-
-          Foo = T.type_alias { T.any(T.anything, T.untyped) }
-        RBI
-      end
-
-      it "serializes them correctly with Sorbet >= 0.5.10820" do
-        @project.require_real_gem("sorbet-static", "0.5.10860")
-        @project.bundle_install!
-
-        @project.tapioca("gem foo")
-
-        assert_project_file_equal("sorbet/rbi/gems/foo@0.0.1.rbi", <<~RBI)
-          # typed: true
-
-          # DO NOT EDIT MANUALLY
-          # This is an autogenerated file for types exported from the `foo` gem.
-          # Please instead update this file by running `bin/tapioca gem foo`.
-
-          Foo = T.type_alias { T.any(T.anything, T::Class[::String]) }
-        RBI
-      end
-    end
-
     describe "compilation of constants of generic types" do
       before do
         @expected_out = <<~OUT

spec/tapioca/runtime/generic_type_registry_spec.rb

@@ -36,19 +36,13 @@ class GenericTypeRegistrySpec < Minitest::Spec
               Tapioca::TypeVariableModule::Type::Member,
               :invariant,
               nil,
-              nil,
-              nil,
-              nil,
             )
 
             fake_type_member2 = Tapioca::TypeVariableModule.new(
               not_actually_generic,
               Tapioca::TypeVariableModule::Type::Member,
               :invariant,
               nil,
-              nil,
-              nil,
-              nil,
             )
 
             GenericTypeRegistry.register_type_variable(not_actually_generic, fake_type_member1)