chore: slightly more consistent type definition layout

rbi/lib/openai/base_model.rbi

@@ -80,10 +80,10 @@ module OpenAI
 
   # When we don't know what to expect for the value.
   class Unknown
-    abstract!
-
     extend OpenAI::Converter
 
+    abstract!
+
     sig { params(other: T.anything).returns(T::Boolean) }
     def self.===(other)
     end
@@ -116,10 +116,10 @@ module OpenAI
 
   # Ruby has no Boolean class; this is something for models to refer to.
   class BooleanModel
-    abstract!
-
     extend OpenAI::Converter
 
+    abstract!
+
     sig { params(other: T.anything).returns(T::Boolean) }
     def self.===(other)
     end
@@ -161,10 +161,10 @@ module OpenAI
   #   We can therefore convert string values to Symbols, but can't convert other
   #   values safely.
   class Enum
-    abstract!
-
     extend OpenAI::Converter
 
+    abstract!
+
     class << self
       # All of the valid Symbol values for this enum.
       sig { overridable.returns(T::Array[T.any(NilClass, T::Boolean, Integer, Float, Symbol)]) }
@@ -210,10 +210,10 @@ module OpenAI
   end
 
   class Union
-    abstract!
-
     extend OpenAI::Converter
 
+    abstract!
+
     class << self
       # @api private
       #
@@ -295,10 +295,10 @@ module OpenAI
 
   # Array of items of a given type.
   class ArrayOf
-    abstract!
-
     include OpenAI::Converter
 
+    abstract!
+
     sig { params(other: T.anything).returns(T::Boolean) }
     def ===(other)
     end
@@ -357,10 +357,10 @@ module OpenAI
 
   # Hash of items of a given type.
   class HashOf
-    abstract!
-
     include OpenAI::Converter
 
+    abstract!
+
     sig { params(other: T.anything).returns(T::Boolean) }
     def ===(other)
     end
@@ -418,10 +418,10 @@ module OpenAI
   end
 
   class BaseModel
-    abstract!
-
     extend OpenAI::Converter
 
+    abstract!
+
     KnownFieldShape = T.type_alias { {mode: T.nilable(Symbol), required: T::Boolean} }
 
     class << self