Notable changes:
- Fix for missing runtime DLLs on Windows
- Enables native Mac ARM64 wheel support
- Startup performance improvements
- Fixes to spec validation for python 3

Bug: 1237202, 1103275, 1219868
Change-Id: I9beeb9dc5e82630d3cc6369a501fa63b11d1321d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/3158553
Commit-Queue: Brian Ryner <bryner@google.com>
Reviewed-by: Dirk Pranke <dpranke@google.com>