Support serial execution and introduce backend preference

[vchuravy]

This is a rebase of #2417

• Support serial backend
• Rebase post Use Adapt.jl to change storage and element type #2212 and KernelAbstraction support

The gist is that we allow the user to choose a ":serial" backend and we merge the CPU backend switch for KernelAbstraction support

[github-actions]

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[codecov]

Codecov Report

Attention: Patch coverage is 45.45455% with 6 lines in your changes missing coverage. Please review.

Project coverage is 89.15%. Comparing base (2bc1208) to head (4a11b04).
Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
src/auxiliary/math.jl	0.00%	6 Missing ⚠️

❗ There is a different number of reports uploaded between BASE (2bc1208) and HEAD (4a11b04). Click for more details.

HEAD has 5 uploads less than BASE

Flag	BASE (2bc1208)	HEAD (4a11b04)
unittests	26	21

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2476      +/-   ##
==========================================
- Coverage   96.67%   89.15%   -7.52%     
==========================================
  Files         507      507              
  Lines       42010    42005       -5     
==========================================
- Hits        40610    37446    -3164     
- Misses       1400     4559    +3159     

Flag	Coverage Δ
unittests	89.15% <45.45%> (-7.52%)	⬇️

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[ranocha]

Thanks! Could you please

• bump the version in

  Trixi.jl/Project.toml

  Line 4 in dbf254b

  version = "0.12.8-DEV"

  to v0.13.0-DEV
• add a NEWS.md entry

?

[vchuravy]

Done!

[ranocha]

Thanks!

[ranocha]

Thanks!