bump compat for SciMLBase.jl to v2

[ranocha]

Closes #1646

[github-actions]

Review checklist

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[ranocha]

I just checked that it uses the new version of SciMLBase.jl in the buildpkg step.

[codecov]

Codecov Report

All modified lines are covered by tests ✅

Comparison is base (0b4bf98) 87.91% compared to head (338f598) 96.11%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1647      +/-   ##
==========================================
+ Coverage   87.91%   96.11%   +8.21%     
==========================================
  Files         418      418              
  Lines       34205    34247      +42     
==========================================
+ Hits        30068    32915    +2847     
+ Misses       4137     1332    -2805     

Flag	Coverage Δ
unittests	96.11% <ø> (+8.21%)	⬆️

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see 55 files with indirect coverage changes

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