CompatHelper: bump compat for Setfield to 0.8, (keep existing compat)

[github-actions]

This pull request changes the compat entry for the Setfield package from 0.4, 0.5, 0.6, 0.7 to 0.4, 0.5, 0.6, 0.7, 0.8.
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 #70 (d0c1aef) into master (ac1fa98) will not change coverage.
The diff coverage is n/a.

❗ Current head d0c1aef differs from pull request most recent head e0f52a4. Consider uploading reports for the commit e0f52a4 to get more accurate results

@@          Coverage Diff           @@
##           master     #70   +/-   ##
======================================
  Coverage    3.44%   3.44%           
======================================
  Files           7       7           
  Lines          87      87           
======================================
  Hits            3       3           
  Misses         84      84           

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