fix: clean up cache by removing missing keys.

Author: sbansal1999

packages/sdk/src/core/flags/flags-manager.ts

@@ -301,6 +301,12 @@ export class CoreFlagsManager implements FlagsManager {
 			const ttl = this.config.cacheTtl ?? 60_000;
 			const staleTime = this.config.staleTime ?? ttl / 2;
 
+			const existingKeys = Array.from(this.cache.keys());
+			const missingKeys = existingKeys.filter((key) => !flags[key]);
+			for (const key of missingKeys) {
+				this.cache.delete(key);
+			}
+
 			for (const [key, result] of Object.entries(flags)) {
 				const cacheKey = getCacheKey(key, user ?? this.config.user);
 				this.cache.set(cacheKey, createCacheEntry(result, ttl, staleTime));