fix: drop message arg when converting assertResponse() to statusCodeEquals()

[bbrala]

Problem

The Drupal 9 AssertLegacyTrait rector converts $this->assertResponse(200, 'message') to $this->assertSession()->statusCodeEquals(200, 'message'). However, WebAssert::statusCodeEquals(int $code) takes no message argument, so the surplus argument produces invalid output.

The sibling rules (assertText, assertRaw, assertNoText, assertNoRaw) already pass processFirstArgumentOnly = true to drop extra arguments; assertResponse was missed.

Reported in GitLab issue: https://git.drupalcode.org/project/rector/-/work_items/3332090

Fix

One-line config change in config/drupal-9/drupal-9.1-deprecations.php (and the matching test config):

-new AssertLegacyTraitConfiguration('assertResponse', 'statusCodeEquals'),
+new AssertLegacyTraitConfiguration('assertResponse', 'statusCodeEquals', '', true, true),

The 4th parameter is isAssertSessionMethod = true (already the default) and the 5th is processFirstArgumentOnly = true, which reduces the call to a single argument.

Tests

• Added a two-argument case ($this->assertResponse(200, 'Some message.'); → $this->assertSession()->statusCodeEquals(200);) to the PHPUnit fixture assert_response.php.inc and to the functional rector_examples / rector_examples_updated fixtures.
• ./vendor/bin/phpunit --filter AssertLegacyTrait is green (27 tests, 28 assertions).