Update changelog for version 2.3.3

[rly]

Prepare for release of PyNWB 2.3.3.

allensdk does not yet support Python 3.11 in part because pynwb does not officially support Python 3.11. This release officially adds Python 3.11 support.

Before merging:

• Major and minor releases: Update package versions in requirements.txt, requirements-dev.txt,
  requirements-doc.txt, requirements-min.txt, environment-ros3.yml, and setup.py as needed.
• Check legal file dates and information in Legal.txt, license.txt, README.rst, docs/source/conf.py,
  and any other locations as needed
• Update setup.py as needed
• Update README.rst as needed
• Update src/pynwb/nwb-schema submodule as needed. Check the version number and commit SHA manually
• Update changelog (set release date) in CHANGELOG.md and any other docs as needed
• Run tests locally including gallery, validation, and streaming tests, and inspect all warnings and outputs
  (python test.py -v -p -i -b -w -r > out.txt 2>&1)
• Test docs locally (make clean, make html)
• Push changes to this PR and make sure all PRs to be included in this release have been merged
• Check that the readthedocs build for this PR succeeds (build latest to pull the new branch, then activate and
  build docs for new branch): https://readthedocs.org/projects/pynwb/builds/

After merging:

1. Create release by following steps in docs/source/make_a_release.rst or use alias git pypi-release [tag] if set up
2. After the CI bot creates the new release (wait ~10 min), update the release notes on the
   GitHub releases page with the changelog
3. Check that the readthedocs "latest" and "stable" builds run and succeed
4. Update conda-forge/pynwb-feedstock with the latest version number
   and SHA256 retrieved from PyPI > PyNWB > Download Files > View hashes for the .tar.gz file. Re-render as needed

[codecov]

Codecov Report

Merging #1706 (5d3d78f) into dev (59e8075) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##              dev    #1706   +/-   ##
=======================================
  Coverage   91.93%   91.93%           
=======================================
  Files          26       26           
  Lines        2592     2592           
  Branches      679      679           
=======================================
  Hits         2383     2383           
  Misses        134      134           
  Partials       75       75           

Flag	Coverage Δ
integration	71.52% <ø> (ø)
unit	83.56% <ø> (ø)

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