fix(scheduling): numpy worker environs are not taking effect

[bojiang]

solution:

• only allow scheduling_strategy to control the env variables
• setting up environ before importing bentoml

WARNING: a breaking change for a not documented public API custom scheduler

[codecov[bot]]

Codecov Report

Merging #2893 (3280c4b) into main (3ec89ec) will decrease coverage by 1.53%. The diff coverage is 21.66%.

:exclamation: Current head 3280c4b differs from pull request most recent head f0b7386. Consider uploading reports for the commit f0b7386 to get more accurate results

@@            Coverage Diff             @@
##             main    #2893      +/-   ##
==========================================
- Coverage   70.88%   69.35%   -1.54%     
==========================================
  Files         103      103              
  Lines        9335     9374      +39     
==========================================
- Hits         6617     6501     -116     
- Misses       2718     2873     +155     

Impacted Files	Coverage Δ
bentoml/_internal/yatai_client/__init__.py	24.06% <6.06%> (-0.94%)	:arrow_down:
bentoml/_internal/yatai_rest_api_client/yatai.py	31.25% <27.27%> (-0.64%)	:arrow_down:
bentoml/_internal/yatai_rest_api_client/schemas.py	93.53% <100.00%> (+0.06%)	:arrow_up:
bentoml/_internal/utils/buildx.py	0.00% <0.00%> (-49.00%)	:arrow_down:
bentoml/_internal/utils/docker.py	34.48% <0.00%> (-34.49%)	:arrow_down:
bentoml/_internal/utils/circus/__init__.py	60.00% <0.00%> (-30.00%)	:arrow_down:
bentoml/_internal/utils/platform.py	66.66% <0.00%> (-8.34%)	:arrow_down:
bentoml/_internal/runner/container.py	83.98% <0.00%> (-6.07%)	:arrow_down:
bentoml/_internal/runner/runner_handle/remote.py	83.87% <0.00%> (-4.31%)	:arrow_down:
bentoml/_internal/runner/utils.py	86.88% <0.00%> (-3.28%)	:arrow_down:
... and 7 more