CompatHelper: bump compat for "FillArrays" to "0.13"

[github-actions]

This pull request changes the compat entry for the FillArrays package from 0.8, 0.9, 0.10, 0.11, 0.12 to 0.8, 0.9, 0.10, 0.11, 0.12, 0.13.

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 #46 (868b957) into master (1c7dc13) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master      #46   +/-   ##
=======================================
  Coverage   90.93%   90.93%           
=======================================
  Files          14       14           
  Lines         905      905           
=======================================
  Hits          823      823           
  Misses         82       82           

Flag	Coverage Δ
unittests	90.93% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 1c7dc13...868b957. Read the comment docs.