chore: refactor server test setup (#3976)

* chore: refactor server test setup

* Close dangling redis connections instead of mocking rate limiter
  specific modules
* Segregate pre and post env test setup

* fix: remove mock file

server/__mocks__/RateLimiter.ts

@@ -1,28 +0,0 @@
-export default class MockRateLimiter {
-  static getRateLimiter() {
-    return {
-      points: 100,
-      consume: jest.fn(),
-    };
-  }
-
-  static setRateLimiter() {
-    //
-  }
-
-  static hasRateLimiter() {
-    return false;
-  }
-}
-
-export const RateLimiterStrategy = new Proxy(
-  {},
-  {
-    get() {
-      return {
-        duration: 60,
-        requests: 10,
-      };
-    },
-  }
-);