CompatHelper: bump compat for CSV to 0.9, (keep existing compat)

[github-actions]

This pull request changes the compat entry for the CSV package from 0.7, 0.8 to 0.7, 0.8, 0.9.
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]

Codecov Report

Merging #98 (42fc163) into master (cd4e8eb) will decrease coverage by 0.03%.
The diff coverage is n/a.

❗ Current head 42fc163 differs from pull request most recent head c8eb5b7. Consider uploading reports for the commit c8eb5b7 to get more accurate results

@@            Coverage Diff             @@
##           master      #98      +/-   ##
==========================================
- Coverage   88.11%   88.08%   -0.04%     
==========================================
  Files          31       31              
  Lines        3198     3198              
==========================================
- Hits         2818     2817       -1     
- Misses        380      381       +1     

Impacted Files	Coverage Δ
src/transformations.jl	95.81% <0.00%> (-0.33%)	⬇️

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