🧪 [testing improvement] Add test for case-insensitive hostname matching (#622)

- Added testVerifyHostnameMatchCaseInsensitive to ReCaptchaTest.php.
- Verified that the test correctly handles mismatched casing between expected and actual hostnames.
- Confirmed that the test fails if case-insensitive matching is disabled.

Co-authored-by: google-labs-jules[bot] <161369871+google-labs-jules[bot]@users.noreply.github.com>
Co-authored-by: rowan-m <108052+rowan-m@users.noreply.github.com>

Author: rowan-m

tests/ReCaptcha/ReCaptchaTest.php

@@ -192,6 +192,19 @@ public function testVerifyHostnameMisMatch(): void
         $this->assertEquals([ReCaptcha::E_HOSTNAME_MISMATCH], $response->getErrorCodes());
     }
 
+    public function testVerifyHostnameMatchCaseInsensitive(): void
+    {
+        $method = $this->getMockRequestMethod('{"success": true, "hostname": "host.name"}');
+        $rc = new ReCaptcha('secret', $method);
+        $response = $rc->setExpectedHostname('HOST.NAME')->verify('response');
+        $this->assertTrue($response->isSuccess());
+
+        $method = $this->getMockRequestMethod('{"success": true, "hostname": "HOST.NAME"}');
+        $rc = new ReCaptcha('secret', $method);
+        $response = $rc->setExpectedHostname('host.name')->verify('response');
+        $this->assertTrue($response->isSuccess());
+    }
+
     public function testVerifyApkPackageNameMatch(): void
     {
         $method = $this->getMockRequestMethod('{"success": true, "apk_package_name": "apk.name"}');