CI: Fixed arch for macOS jobs

[stemann]

macOS-latest is an aarch64 host, while macOS-13 is an x86_64 host - the Julia arch should match.

Also,

• Added permissions required by julia-actions/cache.
• Set a timeout around 3x the time to complete tests.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 73.12%. Comparing base (8472a71) to head (846e178).

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #286      +/-   ##
==========================================
+ Coverage   72.96%   73.12%   +0.16%     
==========================================
  Files          12       12              
  Lines         614      614              
==========================================
+ Hits          448      449       +1     
+ Misses        166      165       -1     

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[maleadt]

Looks like it's every time an assertion failure in PoCL: Could not find a dominating alternative variable. That should be fixed in the next version of PoCL, but it's unfortunate that it got exposed by a KA.jl bump.