Change mbcs encoding to utf-8 in com/win32com/client (#2097)

Pythonwin/pywin/__init__.py

@@ -3,8 +3,5 @@
 # others are looking at it, but it will go away soon!
 is_platform_unicode = 0
 
-# Ditto default_platform_encoding - not referenced and will die.
-default_platform_encoding = "mbcs"
-
 # This one *is* real and used - but in practice can't be changed.
 default_scintilla_encoding = "utf-8"  # Scintilla _only_ supports this ATM

Pythonwin/pywin/tools/hierlist.py

@@ -175,8 +175,6 @@ def AddItem(self, parentHandle, item, hInsertAfter=commctrl.TVI_LAST):
         bitmapSel = self.GetSelectedBitmapColumn(item)
         if bitmapSel is None:
             bitmapSel = bitmapCol
-        ## if isinstance(text, str):
-        ##  text = text.encode("mbcs")
         hitem = self.listControl.InsertItem(
             parentHandle,
             hInsertAfter,

com/win32com/client/genpy.py

@@ -1025,7 +1025,7 @@ def BuildOleItemsFromType(self):
 
         return oleItems, enumItems, recordItems, vtableItems
 
-    def open_writer(self, filename, encoding="mbcs"):
+    def open_writer(self, filename, encoding="utf-8"):
         # A place to put code to open a file with the appropriate encoding.
         # Does *not* set self.file - just opens and returns a file.
         # Actually returns a handle to a temp file - finish_writer then deletes
@@ -1097,7 +1097,7 @@ def do_gen_file_header(self):
         # We assert this is it may indicate somewhere in pywin32 that needs
         # upgrading.
         assert self.file.encoding, self.file
-        encoding = self.file.encoding  # or "mbcs"
+        encoding = self.file.encoding
 
         print(f"# -*- coding: {encoding} -*-", file=self.file)
         print(f"# Created by makepy.py version {makepy_version}", file=self.file)