[MPS] Add version check (#78192)
Use `instancesRespondToSelector:` to test the presence of
`optimizationLevel` in `MPSGraphCompilationDescriptor`, which according
to
https://developer.apple.com/documentation/metalperformanceshadersgraph/mpsgraphcompilationdescriptor/3922624-optimizationlevel
is only available on 12.3 or newer
This works around a limitations of `@available(macOS 12.3, *)` macro in
shared libraries dynamically loaded by apps targeting older runtime.
And deployment target for macos Python conda binaries is 10.14:
```
% otool -l `which python3`
...
Load command 9
cmd LC_BUILD_VERSION
cmdsize 32
platform 1
minos 10.14
sdk 10.14
...
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/78192
Approved by: https://github.com/atalman, https://github.com/seemethere
