PYTHON-6149 Fix condition for minPoolSize validation - #3099

PYTHON-6149

Changes in this PR

• _parse_pool_options only exempted maxPoolSize=None from the minPoolSize <= maxPoolSize check. The docs say both 0 and None mean no limit, and the pool treats both as unlimited. This made MongoClient(maxPoolSize=0, minPoolSize=5) raise ValueError while maxPoolSize=None was accepted.
• The check now skips both 0 and None.

Test Plan

• Manual check on PyMongo 4.18.2:
  • maxPoolSize=0 and maxPoolSize=None, each with minPoolSize=5: accepted.
  • maxPoolSize=10, minPoolSize=20, and minPoolSize=200 against the default max of 100: still raise ValueError.
  • maxPoolSize=10, minPoolSize=10: still accepted.

Checklist

Checklist for Author

• Did you update the changelog (if necessary)?
• Is the intention of the code captured in relevant tests?
• If there are new TODOs, has a related JIRA ticket been created?

Checklist for Reviewer

• Does the title of the PR reference a JIRA Ticket?
• Do you fully understand the implementation? (Would you be comfortable explaining how this code works to someone else?)
• Have you checked for spelling & grammar errors?
• Is all relevant documentation (README or docstring) updated?