Vendor debugpy for VS Code attach debugging

Bundles debugpy 1.7.0 directly in python/ so "Maya: Attach (debugpy)"
works with no per-machine pip install step. Installed via Maya 2022's
own pip so it resolved a version actually compatible with Python 3.7
(Maya 2022's interpreter), then verified import + listen() succeeds
under all three target Maya Python versions (3.7/3.9/3.10).

Also fixes a latent __file__-under-exec() bug in
start_debug_server.py (same pitfall as Maya's own plugin loader,
never hit until this exercised it) and corrects the README's Maya
Python version claim -- 2022 ships Python 3.7, not 3.9 as previously
stated, which was never independently verified until now.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

python/debugpy/_vendored/pydevd/tests_mainloop/gui-wx.py

@@ -0,0 +1,103 @@
+#!/usr/bin/env python
+"""
+A Simple wx example to test PyDev's event loop integration.
+
+To run this:
+1) Enable the PyDev GUI event loop integration for wx
+2) do an execfile on this script
+3) ensure you have a working GUI simultaneously with an
+   interactive console
+
+Ref: Modified from wxPython source code wxPython/samples/simple/simple.py
+"""
+
+if __name__ == '__main__':
+
+    import wx
+    
+    
+    class MyFrame(wx.Frame):
+        """
+        This is MyFrame.  It just shows a few controls on a wxPanel,
+        and has a simple menu.
+        """
+        def __init__(self, parent, title):
+            wx.Frame.__init__(self, parent, -1, title,
+                              pos=(150, 150), size=(350, 200))
+    
+            # Create the menubar
+            menuBar = wx.MenuBar()
+    
+            # and a menu
+            menu = wx.Menu()
+    
+            # add an item to the menu, using \tKeyName automatically
+            # creates an accelerator, the third param is some help text
+            # that will show up in the statusbar
+            menu.Append(wx.ID_EXIT, "E&xit\tAlt-X", "Exit this simple sample")
+    
+            # bind the menu event to an event handler
+            self.Bind(wx.EVT_MENU, self.on_time_to_close, id=wx.ID_EXIT)
+    
+            # and put the menu on the menubar
+            menuBar.Append(menu, "&File")
+            self.SetMenuBar(menuBar)
+    
+            self.CreateStatusBar()
+    
+            # Now create the Panel to put the other controls on.
+            panel = wx.Panel(self)
+    
+            # and a few controls
+            text = wx.StaticText(panel, -1, "Hello World!")
+            text.SetFont(wx.Font(14, wx.SWISS, wx.NORMAL, wx.BOLD))
+            text.SetSize(text.GetBestSize())
+            btn = wx.Button(panel, -1, "Close")
+            funbtn = wx.Button(panel, -1, "Just for fun...")
+    
+            # bind the button events to handlers
+            self.Bind(wx.EVT_BUTTON, self.on_time_to_close, btn)
+            self.Bind(wx.EVT_BUTTON, self.on_fun_button, funbtn)
+    
+            # Use a sizer to layout the controls, stacked vertically and with
+            # a 10 pixel border around each
+            sizer = wx.BoxSizer(wx.VERTICAL)
+            sizer.Add(text, 0, wx.ALL, 10)
+            sizer.Add(btn, 0, wx.ALL, 10)
+            sizer.Add(funbtn, 0, wx.ALL, 10)
+            panel.SetSizer(sizer)
+            panel.Layout()
+    
+    
+        def on_time_to_close(self, evt):
+            """Event handler for the button click."""
+            print("See ya later!")
+            self.Close()
+    
+        def on_fun_button(self, evt):
+            """Event handler for the button click."""
+            print("Having fun yet?")
+    
+    
+    class MyApp(wx.App):
+        def OnInit(self):
+            frame = MyFrame(None, "Simple wxPython App")
+            self.SetTopWindow(frame)
+    
+            print("Print statements go to this stdout window by default.")
+    
+            frame.Show(True)
+            return True
+    
+    
+    if __name__ == '__main__':
+    
+        app = wx.GetApp()
+        if app is None:
+            app = MyApp(redirect=False, clearSigInt=False)
+        else:
+            frame = MyFrame(None, "Simple wxPython App")
+            app.SetTopWindow(frame)
+            print("Print statements go to this stdout window by default.")
+            frame.Show(True)
+