Add musl arm64 build

[kpietraszko]

Hi! There are already builds for musl amd64 and musl armhf architectures, but musl arm64 seems to be missing.
Would you consider adding it?

Great project by the way 👏

[sharkdp]

Sure. I think we should be able to add that here:

numbat/.github/workflows/ci.yml

Lines 156 to 168 in aa96754

	job:
	- { target: aarch64-unknown-linux-gnu , os: ubuntu-20.04, use-cross: true }
	- { target: arm-unknown-linux-gnueabihf , os: ubuntu-20.04, use-cross: true }
	- { target: arm-unknown-linux-musleabihf, os: ubuntu-20.04, use-cross: true }
	- { target: i686-pc-windows-msvc , os: windows-2019 }
	- { target: i686-unknown-linux-gnu , os: ubuntu-20.04, use-cross: true }
	- { target: i686-unknown-linux-musl , os: ubuntu-20.04, use-cross: true }
	- { target: x86_64-apple-darwin , os: macos-13 }
	- { target: aarch64-apple-darwin , os: macos-15 }
	#- { target: x86_64-pc-windows-gnu , os: windows-2019 }
	- { target: x86_64-pc-windows-msvc , os: windows-2019 }
	- { target: x86_64-unknown-linux-gnu , os: ubuntu-20.04, use-cross: true }
	- { target: x86_64-unknown-linux-musl , os: ubuntu-20.04, use-cross: true }

Great project by the way 👏

Thank you!