Remove ErasedFunction

This can be removed now that the reference compiler (3.4.0) no longer
tries to load the symbol of `ErasedFunction`.

Follow up of #18295

Author: nicolasstucki

library/src/scala/runtime/ErasedFunction.scala

@@ -86,7 +86,6 @@ val experimentalDefinitionInLibrary = Set(
 
   // New feature: functions with erased parameters.
   // Need erasedDefinitions enabled.
-  "scala.runtime.ErasedFunction", // will be removed (now using PolyFunction)
   "scala.quoted.Quotes.reflectModule.MethodTypeMethods.erasedParams",
   "scala.quoted.Quotes.reflectModule.MethodTypeMethods.hasErasedParams",
   "scala.quoted.Quotes.reflectModule.TermParamClauseMethods.erasedArgs",