Fix typo `aaarch64->aarch64` (#7141)
copy pasted `--python-platform aaarch64-unknown-linux-gnu` [from the
docs](https://docs.astral.sh/uv/reference/cli/#uv-pip-compile) and got
> error: invalid value 'aaarch64-unknown-linux-gnu' for
'--python-platform <PYTHON_PLATFORM>'
> [possible values: windows, linux, macos, x86_64-pc-windows-msvc,
i686-pc-windows-msvc, x86_64-unknown-linux-gnu, aarch64-apple-darwin,
x86_64-apple-darwin, aarch64-unknown-linux-gnu,
aarch64-unknown-linux-musl, x86_64-unknown-linux-musl,
x86_64-manylinux_2_17, x86_64-manylinux_2_28, x86_64-manylinux_2_31,
aarch64-manylinux_2_17, aarch64-manylinux_2_28, aarch64-manylinux_2_31]
>
> tip: a similar value exists: 'aarch64-unknown-linux-gnu'
