Expand CI matrix, new platforms + renames

[m0nsky]

Changes:

• Renames some of the existing CI runners to make it more clear what platform they actually test
• Pins versions so that CI doesn't randomly break with automatic version updates (like we've recently had with python)
• Adds two new platforms (linux arm64, musl x64)

Before

Check name	Runner	Platform
Test (linux-release)	ubuntu-latest	Linux x64 CPU
Test (windows-release)	windows-2022	Windows x64 CPU
Test (osx-release)	macos-14	macOS ARM64 Metal

After

Check name	Runner	Platform	Change
Linux x64 CPU	ubuntu-24.04	Linux x64 CPU	Renamed + pinned version
Windows x64 CPU	windows-2022	Windows x64 CPU	Renamed
macOS ARM64 Metal	macos-14	macOS ARM64 Metal	Renamed
Linux ARM64 CPU	ubuntu-24.04-arm	Linux aarch64 CPU	New
Linux musl x64 CPU	ubuntu-24.04 (Alpine container)	Linux musl x64 CPU	New

So, after this change, the only platforms that require manual testing when we do a new binary update are:

• Windows Vulkan
• Windows CUDA
• Linux Vulkan
• Linux CUDA