clean up some more imports

[penelopeysm]

This PR removes the blanket using DynamicPPL in Turing.Inference.

[github-actions]

Turing.jl documentation for PR #2589 is available at:
https://TuringLang.github.io/Turing.jl/previews/PR2589/

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 85.50%. Comparing base (e84aec1) to head (b885dab).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2589   +/-   ##
=======================================
  Coverage   85.50%   85.50%           
=======================================
  Files          22       22           
  Lines        1456     1456           
=======================================
  Hits         1245     1245           
  Misses        211      211           

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[coveralls]

Pull Request Test Coverage Report for Build 15594431435

Details

• 16 of 16 (100.0%) changed or added relevant lines in 3 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 85.567%

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Totals
Change from base Build 15497510494:	0.0%
Covered Lines:	1245
Relevant Lines:	1455

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💛 - Coveralls

[sunxd3]

Like it a lot