Extend CUDACore.jl instead of CUDA.jl

[christiangnrd]

This'll cause a lot of confusion from people not using all of CUDA.jl if not fixed.
I also think that either 1.2.0 should get yanked or this be released in 1.2.2 seperate from #81 so that users still on CUDA 5.x don't end up with 1.2.0

@vchuravy

Closes #74

[christiangnrd]

If we REALLY want to keep supporting CUDA 5, I think there's a potentially hacky way to do it with a dummy extension but I think it should be avoided unless we have a concrete example of a user with a good reason to still be on CUDA 5 that needs this functionality

[vchuravy]

Let's make this 1.3?

[codecov]

Codecov Report

❌ Patch coverage is 0% with 7 lines in your changes missing coverage. Please review.
✅ Project coverage is 56.57%. Comparing base (e60c518) to head (a24af4e).
⚠️ Report is 27 commits behind head on main.

Files with missing lines	Patch %	Lines
ext/AtomixCUDACoreExt.jl	0.00%	7 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##             main      #82       +/-   ##
===========================================
- Coverage   92.95%   56.57%   -36.39%     
===========================================
  Files           6       10        +4     
  Lines         142      251      +109     
===========================================
+ Hits          132      142       +10     
- Misses         10      109       +99     

Flag	Coverage Δ
Pkg.test	56.57% <0.00%> (-36.39%)	⬇️

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[christiangnrd]

Can we merge #77 first so that buildkite tests also run on 1.12?

[christiangnrd]

Bump