Raise error if unsupported charset for mysql

`blog$ bin/rails db:create`

Before:
```
Couldn't create database for {"adapter"=>"mysql2", "encoding"=>"utf42", "pool"=>5,
"username"=>"root", "password"=>nil, "socket"=>"/var/run/mysqld/mysqld.sock",
"database"=>"blog_development"}, {:charset=>"utf42"}
(If you set the charset manually, make sure you have a matching collation)
Created database 'blog_development'
Couldn't create database for {"adapter"=>"mysql2", "encoding"=>"utf42", "pool"=>5,
"username"=>"root", "password"=>nil, "socket"=>"/var/run/mysqld/mysqld.sock",
"database"=>"blog_test"}, {:charset=>"utf42"}
(If you set the charset manually, make sure you have a matching collation)
Created database 'blog_test'
```

After:
```
Unsupported charset: '"utf42"'
Couldn't create database for {"adapter"=>"mysql2", "encoding"=>"utf42", "pool"=>5,
"username"=>"root", "password"=>nil, "socket"=>"/var/run/mysqld/mysqld.sock",
"database"=>"blog_development"}
rails aborted!
Mysql2::Error: Unsupported charset: '"utf42"'
...
(stack trace)
...
bin/rails:4:in `<main>'
Tasks: TOP => db:create
(See full trace by running task with --trace)
```

Closes #29683
Related to #27398

1 files changed, 1 insertions, 3 deletions

diff --git a/activerecord/lib/active_record/tasks/mysql_database_tasks.rb b/activerecord/lib/active_record/tasks/mysql_database_tasks.rb
index 2f91884f59..d6a46f7743 100644
--- a/activerecord/lib/active_record/tasks/mysql_database_tasks.rb
+++ b/activerecord/lib/active_record/tasks/mysql_database_tasks.rb
@@ -31,9 +31,7 @@ module ActiveRecord
           end
           establish_connection configuration
         else
-          $stderr.puts error.inspect
-          $stderr.puts "Couldn't create database for #{configuration.inspect}, #{creation_options.inspect}"
-          $stderr.puts "(If you set the charset manually, make sure you have a matching collation)" if configuration["encoding"]
+          raise
         end
       end