Remove benches folder (#4592)

Author: JoviDeCroock

.prettierignore

@@ -14,12 +14,4 @@ package/
 preact-*.tgz
 preact.tgz
 
-# Copied from benches/.gitignore so prettier can ignore these paths too
-benches/dist/
-benches/results/
-benches/logs/
-benches/logs-saved/
-benches/node_modules/
-benches/proxy-packages/*/package-lock.json
-
 package-lock.json