[aclark4life]

PYTHON-6267

Changes in this PR

Prepares the PyMongo 4.20.0 release:

• Sets the version in pymongo/_version.py to 4.20.0.
• Finalizes doc/changelog.rst: sets the release date and adds the "Issues Resolved" section linking to the Jira release notes.

Test Plan

No code changes. pre-commit run --files doc/changelog.rst pymongo/_version.py passes (including rstcheck and synchro).

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?

[Copilot]

🟢 Approval recommended

There are no active review issues for the release-version and changelog updates.

No open issues 🎉

What changed in this PR

Prepares PyMongo 4.20.0 for release by finalizing the package version and changelog.

Changes:

• Sets the package version to 4.20.0, removing the development suffix.
• Dates the release November 12, 2026, and adds a link to the resolved issues in Jira.

File	Description
pymongo/​_version.py	Sets the stable release version to 4.20.0.
doc/​changelog.rst	Finalizes the release date and adds the Issues Resolved section.

_{Review effort: Balanced}

[blink1073]

LGTM