[stubsabot] Bump braintree to 4.26.*

[github-actions[bot]]

Release: https://pypi.org/pypi/braintree/4.26.0 Homepage: https://developer.paypal.com/braintree/docs/reference/overview Repository: https://github.com/braintree/braintree_python Diff: https://github.com/braintree/braintree_python/compare/4.25.0...4.26.0

Stubsabot analysis of the diff between the two releases:

• 2 public Python files have been added: braintree/package_details.py, tests/integration/test_package_tracking.py.
• 0 files included in typeshed's stubs have been deleted.
• 9 files included in typeshed's stubs have been modified or renamed.
• Total lines of Python code added: 440.
• Total lines of Python code deleted: 52.

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[JelleZijlstra]

Stubtest is fine but I think there's some classes that need to be added.