fix: remove class-level .env rename in EncryptionTest to prevent test pollution

Author: gr8man

tests/system/Encryption/EncryptionTest.php

@@ -35,13 +35,9 @@ public static function setUpBeforeClass(): void
 
         CodeIgniterServices::injectMock('superglobals', new Superglobals());
 
-        if (is_file(ROOTPATH . '.env')) {
-            rename(ROOTPATH . '.env', ROOTPATH . '.env.bak');
-
-            putenv('encryption.key');
-            unset($_ENV['encryption.key']);
-            service('superglobals')->unsetServer('encryption.key');
-        }
+        putenv('encryption.key');
+        unset($_ENV['encryption.key']);
+        service('superglobals')->unsetServer('encryption.key');
     }
 
     protected function setUp(): void
@@ -51,15 +47,6 @@ protected function setUp(): void
         $this->encryption = new Encryption();
     }
 
-    public static function tearDownAfterClass(): void
-    {
-        parent::tearDownAfterClass();
-
-        if (is_file(ROOTPATH . '.env.bak')) {
-            rename(ROOTPATH . '.env.bak', ROOTPATH . '.env');
-        }
-    }
-
     /**
      * Covers behavior with config encryption key set or not
      */