Fix ML precommit

[sfc-gh-stan]

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1. What GitHub issue is this PR addressing? Make sure that there is an accompanying issue to your PR.

   Fixes #NNNN

2. Fill out the following pre-review checklist:

   • I am adding a new automated test(s) to verify correctness of my new code
   • I am adding new logging messages
   • I am adding a new telemetry message
   • I am adding new credentials
   • I am adding a new dependency

3. Please describe how your code solves the related issue.

   Fix the ValueErrors in https://ci-dev-151.int.snowflakecomputing.com/job/TestSnowMLSnowpark/70/console by (1) allowing process to have a type hint of None and (2) favoring end_parition's return type hint over that of process.

[codecov]

Codecov Report

Merging #972 (f4ab87d) into main (2aac082) will decrease coverage by 0.03%.
Report is 1 commits behind head on main.
The diff coverage is 85.71%.

@@            Coverage Diff             @@
##             main     #972      +/-   ##
==========================================
- Coverage   98.37%   98.35%   -0.03%     
==========================================
  Files          51       51              
  Lines        9184     9193       +9     
  Branches     1666     1668       +2     
==========================================
+ Hits         9035     9042       +7     
- Misses         59       60       +1     
- Partials       90       91       +1     

Files Changed	Coverage Δ
src/snowflake/snowpark/_internal/udf_utils.py	94.60% <85.71%> (-0.42%)	⬇️

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