fix(ensembler): Remove all pipenv usage

[deadlycoconuts]

Context

Unlike what was mentioned in #411, there was no need for Turing to be using pipenv at all as it was already originally using conda as a package manager. This PR removes all instances where pipenv was used and replaces it with what was originally there before #404.

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 4 lines in your changes missing coverage. Please review.

Project coverage is 96.08%. Comparing base (86a4db5) to head (fbab676).

Files with missing lines	Patch %	Lines
sdk/turing/ensembler.py	0.00%	4 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #412      +/-   ##
==========================================
+ Coverage   95.94%   96.08%   +0.13%     
==========================================
  Files          26       26              
  Lines        2098     2095       -3     
==========================================
  Hits         2013     2013              
+ Misses         85       82       -3     

Flag	Coverage Δ
sdk-test-3.10	96.08% <0.00%> (+0.13%)	⬆️
sdk-test-3.11	96.08% <0.00%> (+0.13%)	⬆️
sdk-test-3.12	96.08% <0.00%> (+0.13%)	⬆️
sdk-test-3.9	96.08% <0.00%> (+0.13%)	⬆️

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