CompatHelper: bump compat for AbstractGPs to 0.5 for package docs, (keep existing compat)

[github-actions]

This pull request changes the compat entry for the AbstractGPs package from 0.3 to 0.3, 0.5 for package docs.
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.

[coveralls]

Pull Request Test Coverage Report for Build 1170910718

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

• For more information on this, see Tracking coverage changes with pull request builds.
• To avoid this issue with future PRs, see these Recommended CI Configurations.
• For a quick fix, rebase this PR at GitHub. Your next report should be accurate.

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 23.529%

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Totals
Change from base Build 935594860:	0.0%
Covered Lines:	16
Relevant Lines:	68

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💛 - Coveralls