CompatHelper: bump compat for Polynomials to 3, (keep existing compat)

[github-actions]

This pull request changes the compat entry for the Polynomials package from 2.0.24 to 2.0.24, 3.
This keeps the compat entries for earlier versions.

Note: I have not tested your package with this new compat entry.
It is your responsibility to make sure that your package tests pass before you merge this pull request.

[codecov-commenter]

Codecov Report

Merging #25 (61e2ca3) into master (3e97c92) will increase coverage by 1.11%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master      #25      +/-   ##
==========================================
+ Coverage   64.20%   65.31%   +1.11%     
==========================================
  Files          23       23              
  Lines        1257     1156     -101     
==========================================
- Hits          807      755      -52     
+ Misses        450      401      -49     

Impacted Files	Coverage Δ
src/FLMM.jl	83.05% <0.00%> (-0.83%)	⬇️
src/FDDE/DelayPECE.jl	94.73% <0.00%> (-0.51%)	⬇️
src/ClosedForm/hankelmatrix.jl	55.31% <0.00%> (-0.46%)	⬇️
src/FPDE/FiniteDiffEx.jl	93.33% <0.00%> (-0.29%)	⬇️
src/FDDE/PI.jl	96.77% <0.00%> (-0.20%)	⬇️
src/GL/GL.jl	0.00% <0.00%> (ø)
src/MTrap.jl	0.00% <0.00%> (ø)
src/Direct.jl	0.00% <0.00%> (ø)
src/GL/TestGL.jl	0.00% <0.00%> (ø)
src/FDDE/L1-PCM.jl	0.00% <0.00%> (ø)
... and 13 more

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