Remove temporary changes to CI setup

[yebai]

See #106 + #109

[KDr2]

Could this be closed?

[yebai]

Probably not, we are still using hard-coded branches in CI scripts.

Libtask.jl/.github/workflows/IntegrationTest.yml

Lines 17 to 18 in 35e2ff2

	- {user: TuringLang, repo: AdvancedPS.jl, ref: releases}
	- {user: TuringLang, repo: Turing.jl, ref: master}

and

Libtask.jl/.github/workflows/BenchmarksAndMicroIntegration.yml

Line 17 in a95702e

- {user: TuringLang, repo: Turing.jl, ref: master}