Remove RCT_FOLLY for RN precompiled feature to work

[billnbell3]

Remove RCT_FOLLY if possible....

• s.dependency "RCT-Folly"
  30 + # Only depend on RCT-Folly if not using precompiled builds
  31 + if ENV['RCT_USE_PREBUILT_RNCORE'] != '1'
  32 + s.dependency "RCT-Folly"
  33 + end