Fix attaching blobs to optimistically-locked records

Explicitly declare inverse associations so ActiveStorage::Attachment touches the original record instance.

Closes #31542.

activestorage/lib/active_storage/attached/macros.rb

@@ -38,7 +38,7 @@ def #{name}=(attachable)
         end
       CODE
 
-      has_one :"#{name}_attachment", -> { where(name: name) }, class_name: "ActiveStorage::Attachment", as: :record
+      has_one :"#{name}_attachment", -> { where(name: name) }, class_name: "ActiveStorage::Attachment", as: :record, inverse_of: :record
       has_one :"#{name}_blob", through: :"#{name}_attachment", class_name: "ActiveStorage::Blob", source: :blob
 
       scope :"with_attached_#{name}", -> { includes("#{name}_attachment": :blob) }
@@ -83,7 +83,7 @@ def #{name}=(attachables)
         end
       CODE
 
-      has_many :"#{name}_attachments", -> { where(name: name) }, as: :record, class_name: "ActiveStorage::Attachment"
+      has_many :"#{name}_attachments", -> { where(name: name) }, as: :record, class_name: "ActiveStorage::Attachment", inverse_of: :record
       has_many :"#{name}_blobs", through: :"#{name}_attachments", class_name: "ActiveStorage::Blob", source: :blob
 
       scope :"with_attached_#{name}", -> { includes("#{name}_attachments": :blob) }