src/environments: increase rate limit for tests

Increase express-rate-limit limit for test environment because we
were seeing "429: Too Many Requests" causing failures of Cypress
in CI.

Author: alanorth

src/environments/environment.test.ts

@@ -45,10 +45,10 @@ export const environment: BuildConfig = {
     // NOTE: Space is capitalized because 'namespace' is a reserved string in TypeScript
     nameSpace: '/angular-dspace',
     baseUrl: 'http://dspace.com/angular-dspace',
-    // The rateLimiter settings limit each IP to a 'limit' of 20 requests per 'windowMs' (1 minute).
+    // The rateLimiter settings limit each IP to a 'limit' of 500 requests per 'windowMs' (1 minute).
     rateLimiter: {
       windowMs: 1 * 60 * 1000, // 1 minute
-      limit: 20, // limit each IP to 20 requests per windowMs
+      limit: 500, // limit each IP to 500 requests per windowMs
       ipv6Subnet: 56,
     },
     useProxies: true,