Update docs to reflect legacy driver removal

- Remove the "New and old driver" section from AGENTS.md
- Remove stale plugin test commands from README.md (the root-level
  "composer run test" was removed along with the legacy driver)
- Remove PHPMyAdmin attribution from readme.txt (the PHPMyAdmin/sql-parser
  code was only used by the deleted legacy lexer)

Author: JanJakes

AGENTS.md

@@ -28,15 +28,6 @@ The codebase is pure PHP with zero dependencies. It supports PHP 7.2 through 8.5
 MySQL syntax from version 5.7 onward, and requires SQLite 3.37.0 or newer
 (with legacy mode down to 3.27.0).
 
-### New and old driver
-At the moment, the project includes two MySQL-on-SQLite driver implementations:
-1. A new, AST-based MySQL-on-SQLite driver (`class-wp-pdo-mysql-on-sqlite.php`).
-2. A legacy, token-based MySQL-to-SQLite translator (`class-wp-sqlite-translator.php`).
-
-This state is temporary. The new driver will fully replace the legacy one. New features
-must always be implemented in the new driver. The legacy driver can receive small fixes.
-The new driver is under a `WP_SQLITE_AST_DRIVER` feature flag, but it is widely used.
-
 ## Commands
 The codebase is written in PHP and Composer is used to manage the project.
 The following commands are useful for development and testing:
@@ -54,10 +45,7 @@ composer run test                       # Run unit tests
 composer run test tests/SomeTest.php    # Run specific unit test file
 composer run test -- --filter testName  # Run specific unit test class/method
 
-# SQLite Database Integration plugin tests
-composer run test                       # Run unit tests
-composer run test tests/SomeTest.php    # Run specific unit test file
-composer run test -- --filter testName  # Run specific unit test class/method
+# SQLite Database Integration plugin E2E tests
 composer run test-e2e                   # Run E2E tests (Playwright via WP env)
 
 # WordPress tests

README.md

@@ -43,10 +43,7 @@ composer run test                       # Run unit tests
 composer run test tests/SomeTest.php    # Run specific unit test file
 composer run test -- --filter testName  # Run specific unit test class/method
 
-# SQLite Database Integration plugin tests
-composer run test                       # Run unit tests
-composer run test tests/SomeTest.php    # Run specific unit test file
-composer run test -- --filter testName  # Run specific unit test class/method
+# SQLite Database Integration plugin E2E tests
 composer run test-e2e                   # Run E2E tests (Playwright via WP env)
 
 # WordPress tests

packages/plugin-sqlite-database-integration/readme.txt

@@ -15,8 +15,6 @@ SQLite integration plugin by the WordPress Team.
 
 The SQLite plugin is a community, feature plugin. The intent is to allow testing an SQLite integration with WordPress and gather feedback, with the goal of eventually landing it in WordPress core.
 
-This feature plugin includes code from the PHPMyAdmin project (specifically parts of the PHPMyAdmin/sql-parser library), licensed under the GPL v2 or later. More info on the PHPMyAdmin/sql-parser library can be found on [GitHub](https://github.com/phpmyadmin/sql-parser).
-
 == Frequently Asked Questions ==
 
 = What is the purpose of this plugin? =