Update remaining migration version 7.2 to 8.0 [ci-skip]

Author: kamipo

guides/source/association_basics.md

@@ -44,7 +44,7 @@ Without associations, creating and deleting books for that author would require
 a tedious and manual process. Here's what that would look like:
 
 ```ruby
-class CreateAuthors < ActiveRecord::Migration[7.2]
+class CreateAuthors < ActiveRecord::Migration[8.0]
   def change
     create_table :authors do |t|
       t.string :name
@@ -193,7 +193,7 @@ Rails will look for a class named `Authors` instead of `Author`.
 The corresponding migration might look like this:
 
 ```ruby
-class CreateBooks < ActiveRecord::Migration[7.2]
+class CreateBooks < ActiveRecord::Migration[8.0]
   def change
     create_table :authors do |t|
       t.string :name
@@ -435,7 +435,7 @@ is declared.
 The corresponding migration might look like this:
 
 ```ruby
-class CreateSuppliers < ActiveRecord::Migration[7.2]
+class CreateSuppliers < ActiveRecord::Migration[8.0]
   def change
     create_table :suppliers do |t|
       t.string :name
@@ -656,7 +656,7 @@ model is pluralized when declaring a `has_many` association.
 The corresponding migration might look like this:
 
 ```ruby
-class CreateAuthors < ActiveRecord::Migration[7.2]
+class CreateAuthors < ActiveRecord::Migration[8.0]
   def change
     create_table :authors do |t|
       t.string :name
@@ -988,7 +988,7 @@ Diagram](images/association_basics/has_many_through.png)
 The corresponding migration might look like this:
 
 ```ruby
-class CreateAppointments < ActiveRecord::Migration[7.2]
+class CreateAppointments < ActiveRecord::Migration[8.0]
   def change
     create_table :physicians do |t|
       t.string :name
@@ -1020,7 +1020,7 @@ key](active_record_composite_primary_keys.html) for the join table in the
 `has_many :through` relationship like below:
 
 ```ruby
-class CreateAppointments < ActiveRecord::Migration[7.2]
+class CreateAppointments < ActiveRecord::Migration[8.0]
   def change
     #  ...
     create_table :appointments, primary_key: [:physician_id, :patient_id] do |t|
@@ -1131,7 +1131,7 @@ Diagram](images/association_basics/has_one_through.png)
 The corresponding migration to set up these associations might look like this:
 
 ```ruby
-class CreateAccountHistories < ActiveRecord::Migration[7.2]
+class CreateAccountHistories < ActiveRecord::Migration[8.0]
   def change
     create_table :suppliers do |t|
       t.string :name
@@ -1186,7 +1186,7 @@ manage the relationship between the associated records. The corresponding
 migration might look like this:
 
 ```ruby
-class CreateAssembliesAndParts < ActiveRecord::Migration[7.2]
+class CreateAssembliesAndParts < ActiveRecord::Migration[8.0]
   def change
     create_table :assemblies do |t|
       t.string :name
@@ -1471,7 +1471,7 @@ To implement these associations, you'll need to create the corresponding
 database tables and set up the foreign key. Here's an example migration:
 
 ```ruby
-class CreateSuppliers < ActiveRecord::Migration[7.2]
+class CreateSuppliers < ActiveRecord::Migration[8.0]
   def change
     create_table :suppliers do |t|
       t.string :name
@@ -1607,7 +1607,7 @@ foreign key column (`imageable_id`) and a type column (`imageable_type`) in the
 model:
 
 ```ruby
-class CreatePictures < ActiveRecord::Migration[7.2]
+class CreatePictures < ActiveRecord::Migration[8.0]
   def change
     create_table :pictures do |t|
       t.string  :name
@@ -1631,7 +1631,7 @@ recommended to use `t.references` or its alias `t.belong_to` and specify
 it automatically adds both the foreign key and type columns to the table.
 
 ```ruby
-class CreatePictures < ActiveRecord::Migration[7.2]
+class CreatePictures < ActiveRecord::Migration[8.0]
   def change
     create_table :pictures do |t|
       t.string :name
@@ -1704,7 +1704,7 @@ To support this relationship, we need to add a `manager_id` column to the
 manager).
 
 ```ruby
-class CreateEmployees < ActiveRecord::Migration[7.2]
+class CreateEmployees < ActiveRecord::Migration[8.0]
   def change
     create_table :employees do |t|
       # Add a belongs_to reference to the manager, which is an employee.
@@ -2176,7 +2176,7 @@ the books table. For a brand new table, the migration might look something like
 this:
 
 ```ruby
-class CreateBooks < ActiveRecord::Migration[7.2]
+class CreateBooks < ActiveRecord::Migration[8.0]
   def change
     create_table :books do |t|
       t.datetime   :published_at
@@ -2190,7 +2190,7 @@ end
 Whereas for an existing table, it might look like this:
 
 ```ruby
-class AddAuthorToBooks < ActiveRecord::Migration[7.2]
+class AddAuthorToBooks < ActiveRecord::Migration[8.0]
   def change
     add_reference :books, :author
   end
@@ -2230,7 +2230,7 @@ You can then fill out the migration and ensure that the table is created without
 a primary key.
 
 ```ruby
-class CreateAssembliesPartsJoinTable < ActiveRecord::Migration[7.2]
+class CreateAssembliesPartsJoinTable < ActiveRecord::Migration[8.0]
   def change
     create_table :assemblies_parts, id: false do |t|
       t.bigint :assembly_id
@@ -2251,7 +2251,7 @@ are you forgot to set `id: false` when creating your migration.
 For simplicity, you can also use the method `create_join_table`:
 
 ```ruby
-class CreateAssembliesPartsJoinTable < ActiveRecord::Migration[7.2]
+class CreateAssembliesPartsJoinTable < ActiveRecord::Migration[8.0]
   def change
     create_join_table :assemblies, :parts do |t|
       t.index :assembly_id
@@ -2271,7 +2271,7 @@ The main difference in schema implementation between creating a join table for
 `has_many :through` requires an `id`.
 
 ```ruby
-class CreateAppointments < ActiveRecord::Migration[7.2]
+class CreateAppointments < ActiveRecord::Migration[8.0]
   def change
     create_table :appointments do |t|
       t.belongs_to :physician

guides/source/getting_started.md

@@ -412,7 +412,7 @@ database-agnostic.
 Let's take a look at the contents of our new migration file:
 
 ```ruby
-class CreateArticles < ActiveRecord::Migration[7.2]
+class CreateArticles < ActiveRecord::Migration[8.0]
   def change
     create_table :articles do |t|
       t.string :title
@@ -1351,7 +1351,7 @@ In addition to the model, Rails has also made a migration to create the
 corresponding database table:
 
 ```ruby
-class CreateComments < ActiveRecord::Migration[7.2]
+class CreateComments < ActiveRecord::Migration[8.0]
   def change
     create_table :comments do |t|
       t.string :commenter