Implement fix for voption with optional parameter syntax (?x=)

Based on analysis:
1. CheckExpressions.fs line 9937: Don't wrap caller arg type when
   SupportValueOptionsAsOptionalParameters feature is enabled
2. MethodCalls.fs CalleeSide branch: Return calledArgTy as-is

This allows voption and option types to work with ?x= syntax by not
creating double-wrapping when the parameter is already optional-typed.

Related to #19074

Co-authored-by: T-Gro <46543583+T-Gro@users.noreply.github.com>

Author: Copilot

src/Compiler/Checking/MethodCalls.fs

@@ -379,7 +379,7 @@ let AdjustCalledArgTypeForOptionals (infoReader: InfoReader) ad enforceNullableO
 
         // FSharpMethod(?x = arg), optional F#-style argument
         | CalleeSide ->
-            // In this case, the called argument will already have option type
+            // In this case, the called argument will already have option/voption type
             calledArgTy, TypeDirectedConversionUsed.No, None
 
         | NotOptional ->