add support for building wheels for windows on arm64 (#920)

* add support for building wheels for windows on arm64

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* Fix main_platform_test.py

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* Remove unrequired explicit nuget source

* add python arm64 3.9.9 version

* extend update_pythons.py to add win/arm64 support

* update documentation for new win/arm64 platform

* style: include ARM64 in literal

* Fix python 3.9 identifier for win_arm64

* Fix table layout issues in README and add note about arm64 pip issue

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Henry Schreiner <HenrySchreinerIII@gmail.com>

cibuildwheel/architecture.py

@@ -29,6 +29,7 @@ class Architecture(Enum):
     # windows archs
     x86 = "x86"
     AMD64 = "AMD64"
+    ARM64 = "ARM64"
 
     # Allow this to be sorted
     def __lt__(self, other: "Architecture") -> bool:
@@ -83,7 +84,7 @@ class Architecture(Enum):
         elif platform == "macos":
             return {Architecture.x86_64, Architecture.arm64, Architecture.universal2}
         elif platform == "windows":
-            return {Architecture.x86, Architecture.AMD64}
+            return {Architecture.x86, Architecture.AMD64, Architecture.ARM64}
         else:
             assert_never(platform)