chore: Build Python protos during sphinx build

[felixwang9817]

What this PR does / why we need it:

Which issue(s) this PR fixes:

Fixes #

[achals]

This assumes make is installed in the rtd environment

[felixwang9817]

updated

[codecov-commenter]

Codecov Report

Merging #3123 (8e14166) into master (1f5b1e0) will decrease coverage by 9.26%.
The diff coverage is n/a.

❗ Current head 8e14166 differs from pull request most recent head 8f3f623. Consider uploading reports for the commit 8f3f623 to get more accurate results

@@            Coverage Diff             @@
##           master    #3123      +/-   ##
==========================================
- Coverage   67.13%   57.86%   -9.27%     
==========================================
  Files         177      214      +37     
  Lines       15894    17899    +2005     
==========================================
- Hits        10670    10358     -312     
- Misses       5224     7541    +2317     

Flag	Coverage Δ
integrationtests	?
unittests	57.86% <ø> (?)

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

Impacted Files	Coverage Δ
...sts/integration/registration/test_universal_cli.py	20.20% <0.00%> (-79.80%)	⬇️
...ts/integration/offline_store/test_offline_write.py	26.08% <0.00%> (-73.92%)	⬇️
...fline_store/test_universal_historical_retrieval.py	28.75% <0.00%> (-71.25%)	⬇️
...ests/integration/e2e/test_python_feature_server.py	29.50% <0.00%> (-70.50%)	⬇️
...dk/python/tests/integration/e2e/test_validation.py	27.55% <0.00%> (-69.30%)	⬇️
...s/integration/registration/test_universal_types.py	32.25% <0.00%> (-67.75%)	⬇️
sdk/python/feast/infra/online_stores/redis.py	28.39% <0.00%> (-66.67%)	⬇️
sdk/python/tests/integration/e2e/test_usage_e2e.py	33.87% <0.00%> (-66.13%)	⬇️
sdk/python/tests/data/data_creator.py	34.78% <0.00%> (-65.22%)	⬇️
...n/tests/integration/registration/test_inference.py	35.71% <0.00%> (-64.29%)	⬇️
... and 161 more

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

[kevjumba]

/lgtm

[feast-ci-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: felixwang9817, kevjumba

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [felixwang9817,kevjumba]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment