CompatHelper: bump compat for Libtask to 0.9, (keep existing compat)

[github-actions]

This pull request changes the compat entry for the Libtask package from 0.8.8 to 0.8.8, 0.9.
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.

[github-actions]

Turing.jl documentation for PR #2548 is available at:
https://TuringLang.github.io/Turing.jl/previews/PR2548/

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 84.27%. Comparing base (05110bd) to head (48331b2).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2548   +/-   ##
=======================================
  Coverage   84.27%   84.27%           
=======================================
  Files          21       21           
  Lines        1456     1456           
=======================================
  Hits         1227     1227           
  Misses        229      229           

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[coveralls]

Pull Request Test Coverage Report for Build 14940025599

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 84.272%

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Totals
Change from base Build 14925677192:	0.0%
Covered Lines:	1227
Relevant Lines:	1456

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💛 - Coveralls