style: global_namespace_import true

[kenjis]

Description

• change global_namespace_import to true
  • import global class only
  • see https://github.com/FriendsOfPHP/PHP-CS-Fixer/blob/2.19/doc/rules/import/global_namespace_import.rst
• update only test code

--- a/src/CodeIgniter4.php
+++ b/src/CodeIgniter4.php
@@ -171,7 +171,7 @@ final class CodeIgniter4 extends AbstractRuleset
                 'fix_inline'     => true,
                 'replacements'   => ['inheritDocs' => 'inheritDoc'],
             ],
-            'global_namespace_import'     => false,
+            'global_namespace_import'     => true,
             'group_import'                => false,
             'header_comment'              => false, // false by default
             'heredoc_indentation'         => ['indentation' => 'start_plus_one'],

Checklist:

• Securely signed commits
• [] Component(s) with PHPDoc blocks, only if necessary or adds value
• [] Unit testing, with >80% coverage
• [] User guide updated
• Conforms to style guide