Prepare for release of PyNWB 2.8.0

[rly]

Before merging:

• [x] Make sure all PRs to be included in this release have been merged to dev.
• [x] Major and minor releases: Update package versions in requirements.txt, requirements-dev.txt, requirements-doc.txt, requirements-opt.txt, and environment-ros3.yml to the latest versions, and update dependency ranges in pyproject.toml and minimums in requirements-min.txt as needed. Run pip install pur && pur -r requirements-dev.txt -r requirements.txt -r requirements-opt.txt and manually update environment-ros3.yml.
• [x] Check legal file dates and information in Legal.txt, license.txt, README.rst, docs/source/conf.py, and any other locations as needed
• [x] Update pyproject.toml as needed
• [x] Update README.rst as needed
• [x] Update src/pynwb/nwb-schema submodule as needed. Check the version number and commit SHA manually. Make sure we are using the latest release and not the latest commit on the main branch.
• [x] Update changelog (set release date) in CHANGELOG.md and any other docs as needed
• [x] 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). Try to remove all warnings.
• [x] Test docs locally and inspect all warnings and outputs cd docs; make clean && make html
• [x] After pushing this branch to GitHub, manually trigger the "Run all tests" GitHub Actions workflow on this branch by going to https://github.com/NeurodataWithoutBorders/pynwb/actions/workflows/run_all_tests.yml, selecting "Run workflow" on the right, selecting this branch, and clicking "Run workflow". Make sure all tests pass.
• [x] Check that the readthedocs build for this PR succeeds (see the PR check)

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 "stable" build runs and succeeds
4. Either monitor conda-forge/pynwb-feedstock for the regro-cf-autotick-bot bot to create a PR updating the version of HDMF to the latest PyPI release, usually within 24 hours of release, or manually create a PR updating recipe/meta.yaml with the latest version number and SHA256 retrieved from PyPI > PyNWB > Download Files > View hashes for the .tar.gz file. Re-render and update dependencies as needed.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 91.88%. Comparing base (a7d585e) to head (2964843). Report is 15 commits behind head on dev.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## dev #1910 +/- ## ========================================== + Coverage 91.62% 91.88% +0.26% ========================================== Files 27 27 Lines 2651 2651 Branches 692 692 ========================================== + Hits 2429 2436 +7 + Misses 149 142 -7 Partials 73 73 ``` | [Flag](https://app.codecov.io/gh/NeurodataWithoutBorders/pynwb/pull/1910/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=NeurodataWithoutBorders) | Coverage Δ | | |---|---|---| | [integration](https://app.codecov.io/gh/NeurodataWithoutBorders/pynwb/pull/1910/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=NeurodataWithoutBorders) | `72.80% <ø> (ø)` | | | [unit](https://app.codecov.io/gh/NeurodataWithoutBorders/pynwb/pull/1910/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=NeurodataWithoutBorders) | `83.96% <ø> (+0.26%)` | :arrow_up: | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=NeurodataWithoutBorders#carryforward-flags-in-the-pull-request-comment) to find out more.

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[rly]

I temporarily limited zarr<2.18.0 in requirements-doc.txt so that the documentation builds while we resolve issues with zarr>=2.18.0 in hdmf-zarr. Otherwise this release would not have a corresponding readthedocs page.