ci: Update postgres tests to use testcontainers

[achals]

What this PR does / why we need it:

Which issue(s) this PR fixes:

Fixes #

[codecov-commenter]

Codecov Report

Merging #2650 (53a0170) into master (5b4b07f) will decrease coverage by 0.16%.
The diff coverage is 56.56%.

@@            Coverage Diff             @@
##           master    #2650      +/-   ##
==========================================
- Coverage   80.65%   80.49%   -0.17%     
==========================================
  Files         163      163              
  Lines       13734    13815      +81     
==========================================
+ Hits        11077    11120      +43     
- Misses       2657     2695      +38     

Flag	Coverage Δ
integrationtests	71.22% <61.53%> (-0.41%)	⬇️
unittests	58.61% <50.50%> (-0.04%)	⬇️

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

Impacted Files	Coverage Δ
...line_stores/contrib/postgres_repo_configuration.py	100.00% <ø> (ø)
...thon/feast/infra/online_stores/contrib/postgres.py	32.69% <ø> (ø)
setup.py	0.00% <ø> (ø)
...n/feature_repos/universal/data_sources/postgres.py	57.31% <52.85%> (+3.74%)	⬆️
sdk/python/tests/conftest.py	81.50% <65.51%> (-3.33%)	⬇️
sdk/python/tests/utils/online_read_write_test.py	93.54% <0.00%> (-6.46%)	⬇️
.../integration/online_store/test_online_retrieval.py	96.84% <0.00%> (-3.16%)	⬇️
...ython/feast/embedded_go/online_features_service.py	89.65% <0.00%> (-0.87%)	⬇️

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[adchia]

/lgtm

[feast-ci-bot]

[APPROVALNOTIFIER] This PR is APPROVED

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