yarn: remove conflicts_with corepack

Signed-off-by: Rui Chen <[email protected]>

Author: chenrui333

Formula/y/yarn.rb

@@ -17,7 +17,6 @@ class Yarn < Formula
   depends_on "node" => :test
 
   conflicts_with "hadoop", because: "both install `yarn` binaries"
-  conflicts_with "corepack", because: "both install `yarn` and `yarnpkg` binaries"
 
   def install
     libexec.install buildpath.glob("*")