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-1.7.0.dist-info/METADATA

@@ -0,0 +1,26 @@
+Metadata-Version: 2.1
+Name: debugpy
+Version: 1.7.0
+Summary: An implementation of the Debug Adapter Protocol for Python
+Home-page: https://aka.ms/debugpy
+Author: Microsoft Corporation
+Author-email: ptvshelp@microsoft.com
+License: MIT
+Project-URL: Source, https://github.com/microsoft/debugpy
+Classifier: Development Status :: 5 - Production/Stable
+Classifier: Programming Language :: Python :: 3.7
+Classifier: Programming Language :: Python :: 3.8
+Classifier: Programming Language :: Python :: 3.9
+Classifier: Programming Language :: Python :: 3.10
+Classifier: Topic :: Software Development :: Debuggers
+Classifier: Operating System :: Microsoft :: Windows
+Classifier: Operating System :: MacOS
+Classifier: Operating System :: POSIX
+Classifier: License :: OSI Approved :: MIT License
+Requires-Python: >=3.7
+Description-Content-Type: text/markdown
+License-File: LICENSE
+
+debugpy is an implementation of the Debug Adapter Protocol for Python.
+
+The source code and the issue tracker is [hosted on GitHub](https://github.com/microsoft/debugpy/).