CompatHelper: bump compat for Ipopt to 1, (keep existing compat)

[github-actions]

This pull request changes the compat entry for the Ipopt package from 0.5, 0.6 to 0.5, 0.6, 1.
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 #27 (7d63f05) into master (dd38609) will decrease coverage by 3.73%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master      #27      +/-   ##
==========================================
- Coverage   33.17%   29.44%   -3.74%     
==========================================
  Files           1        1              
  Lines         642      557      -85     
==========================================
- Hits          213      164      -49     
+ Misses        429      393      -36     

Impacted Files	Coverage Δ
src/RegisterOptimize.jl	29.44% <0.00%> (-3.74%)	⬇️

---

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 dd38609...7d63f05. Read the comment docs.