Refactor CI pip installs

[ascillitoe]

Alibi Detect equivalent of SeldonIO/alibi#817 and SeldonIO/alibi#818.

[codecov-commenter]

Codecov Report

Merging #673 (957f1db) into master (42c5f16) will decrease coverage by 0.16%.
The diff coverage is n/a.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #673      +/-   ##
==========================================
- Coverage   79.12%   78.95%   -0.17%     
==========================================
  Files         126      126              
  Lines        8895     8859      -36     
==========================================
- Hits         7038     6995      -43     
- Misses       1857     1864       +7     

Flag	Coverage Δ
macos-latest-3.10	?
ubuntu-latest-3.10	?
ubuntu-latest-3.7	?
ubuntu-latest-3.8	?
ubuntu-latest-3.9	78.95% <ø> (ø)
windows-latest-3.9	?

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
alibi_detect/utils/_types.py	79.54% <0.00%> (-18.19%)	⬇️
alibi_detect/utils/frameworks.py	88.88% <0.00%> (-3.71%)	⬇️
alibi_detect/saving/schemas.py	97.02% <0.00%> (-0.17%)	⬇️
alibi_detect/utils/missing_optional_dependency.py	94.28% <0.00%> (-0.16%)	⬇️
alibi_detect/datasets.py	68.55% <0.00%> (-0.14%)	⬇️
alibi_detect/utils/fetching/fetching.py	0.00% <0.00%> (ø)
alibi_detect/cd/base.py	91.19% <0.00%> (+0.21%)	⬆️
alibi_detect/od/vae.py	90.36% <0.00%> (+1.07%)	⬆️