CompatHelper: bump compat for KernelFunctions to 0.11, (keep existing compat)

[github-actions]

This pull request changes the compat entry for the KernelFunctions package from 0.9, 0.10 to 0.9, 0.10, 0.11.
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

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 96.21%. Comparing base (99e1ee3) to head (5ce409e).

Additional details and impacted files

@@            Coverage Diff             @@
##            main     #448       +/-   ##
==========================================
+ Coverage   0.26%   96.21%   +95.95%     
==========================================
  Files         12       12               
  Lines        382      396       +14     
==========================================
+ Hits           1      381      +380     
+ Misses       381       15      -366     

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[github-actions]

AbstractGPs.jl documentation for PR #448 is available at:
https://JuliaGaussianProcesses.github.io/AbstractGPs.jl/previews/PR448/