Remove unused dependency

Forgot to remove this after refactoring DocumentRoot to use LocalCache.

Author: trowski

composer.json

@@ -35,7 +35,6 @@
         "amphp/http-server": "^3",
         "amphp/http": "^2-dev",
         "amphp/pipeline": "^1",
-        "cash/lrucache": "^1",
         "revolt/event-loop": "^1 || ^0.2.4"
     },
     "require-dev": {