Use assertEqual instead of assertEquals for Python 3.11 compatibility.

[tirkarthi]

What does this PR do?

Use assertEqual instead of assertEquals for Python 3.11 compatibility. The deprecated aliases were removed in python/cpython#28268

Motivation

Adds Python 3.11 support for tests.

Testing Guidelines

Additional Notes

Types of Changes

• Bug fix
• New feature
• Breaking change
• Misc (docs, refactoring, dependency upgrade, etc.)

Check all that apply

• This PR's description is comprehensive
• This PR contains breaking changes that are documented in the description
• This PR introduces new APIs or parameters that are documented and unlikely to change in the foreseeable future
• This PR impacts documentation, and it has been updated (or a ticket has been logged)
• This PR's changes are covered by the automated tests
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[tianchu]

Thank you @tirkarthi very much for catching these! 🙇‍♂️