feat: update vrs refs to 2.1.0-snapshot.2026-02.2

[korikuzma]

Link to the corresponding Issue.

N/A (sorry, didn't make one since it's a small thing)

Summary of the Pull Request.

There were some bugs in the VRS snapshot (see https://github.com/ga4gh/vrs/releases/tag/2.1.0-snapshot.2026-02.2)

Pull Request checklist:

• Does the title of this Pull Request reference the corresponding Issue?
• Is the branch validating against pre-commit hooks? Run pre-commit run --all-files from the root directory.
• Is the branch passing tests? Run pytest tests/ from the root directory.

If the schema or examples were contributed to:

• Were the schema def/ and json/ files recompiled and committed? Run cd schema; make all from the root directory.
• If constraints or recipes were added, have they been added to the readthedocs? To do so, you can revise the appropriate file within docs/source/concepts/.
• Has documentation been regenerated and committed? Run cd docs; make clean watch & from the root directory to compile documentation.
• Have tests been created or updated?