Fix Standard Error Redirection for composer plugin (#5935)

plugins/composer/composer.plugin.zsh

@@ -52,4 +52,4 @@ alias cgrm='composer global remove'
 alias cget='curl -s https://getcomposer.org/installer | php'
 
 # Add Composer's global binaries to PATH
-export PATH=$PATH:$(composer global config bin-dir --absolute) 2>/dev/null
+export PATH=$PATH:$(composer global config bin-dir --absolute 2>/dev/null)