This pull request moves us to Microsoft.Windows.CppWinRT 2.0.210825.3.
Notable improvements from 2.0.210309.3:
* Restored Windows 7 functionality
* C++20 ranges support
* `capture` now works with a raw pointer
* `hstring::starts_with` and `hstring::ends_with` (C++20)
Unit/Functional Tests:
Summary: Total=7728, Passed=7571, Failed=10, Blocked=0, Not Run=0, Skipped=147
Local Tests:
Summary: Total=163, Passed=158, Failed=5, Blocked=0, Not Run=0, Skipped=0
The above failures are (1) in UIA tests for conhost/WT (which do not work here) or
(2) in already known-broken local tests.