[MNT] Abandon intel MacOS CI test runs

[TonyBagnall]

Describe the feature or idea you want to propose

our macOS tests cause the majority of fails we see. These tests are based on intel Mac OS. Chris is trying to switch over to M1 based tests in #1585

I think the current tests we run are not only pointless, but actually counter productive.

the main source of bugs from mac is due to results reproduction, since numerics are different. The problem is, they are also different between M1 and Intel MacOS. Passing one does not mean you pass the other. This makes the CI ones effectively meaningless. Further, we cannot locally run the CI tests since none of us have an intel based mac.

We also have a problem with #1144. The fixes strangely hang on the CI, but this is not reproducible with M1. I believe tensorflow are no longer supporting intel based tests.

Describe your proposed solution

I think we just abandon all the mac tests and work towards the M1 tests in #1585

Describe alternatives you've considered, if relevant

We could just leave them in, but they are holding up the solution to #1144 where the CI just hangs.

Additional context

No response

[TonyBagnall]

not sure if this is Mac or CI related,

[TonyBagnall]

MacOS related bugs
#324
#622

[TonyBagnall]

and this
#1421