fix platform_machine for macos arm (#3267)

## Summary

based on PEP 508 the `platform_machine` should be same as
`platform.machine()` output:
https://peps.python.org/pep-0508/#environment-markers

From my macOS M2 

```python
In [1]: import platform

In [2]: platform.machine()
Out[2]: 'arm64'
```

I napari we also use `arm64` in requirements and it works as expected: 

9fcf63e69a/pyproject.toml (L120)

## Test Plan

<!-- How was it tested? -->

crates/uv-configuration/src/target_triple.rs

@@ -143,7 +143,7 @@ impl TargetTriple {
         match self {
             Self::Windows | Self::X8664PcWindowsMsvc => "x86_64",
             Self::Linux | Self::X8664UnknownLinuxGnu => "x86_64",
-            Self::Macos | Self::Aarch64AppleDarwin => "aarch64",
+            Self::Macos | Self::Aarch64AppleDarwin => "arm64",
             Self::X8664AppleDarwin => "x86_64",
             Self::Aarch64UnknownLinuxGnu => "aarch64",
             Self::Aarch64UnknownLinuxMusl => "aarch64",