remove unused polyfills from tests

Author: isaacs

test/basic.ts

@@ -1,7 +1,3 @@
-if (typeof performance === 'undefined') {
-  global.performance = require('perf_hooks').performance
-}
-
 import { createRequire } from 'module'
 import t from 'tap'
 import { LRUCache as LRU } from '../dist/esm/index.js'

test/fetch.ts

@@ -1,6 +1,3 @@
-if (typeof performance === 'undefined') {
-  global.performance = require('perf_hooks').performance
-}
 import t from 'tap'
 import { BackgroundFetch, LRUCache } from '../dist/esm/index.js'
 import { expose } from './fixtures/expose.js'

test/ttl.ts

@@ -1,7 +1,3 @@
-if (typeof performance === 'undefined') {
-  global.performance = require('perf_hooks').performance
-}
-
 import t, { Test } from 'tap'
 import { LRUCache } from '../dist/esm/index.js'
 import { expose } from './fixtures/expose.js'