feat!: utilize async lock to overcome dangerous race conditions

[tomasvotava]

Brought into light by @parikls in #186

Closes #186

Summary by CodeRabbit

• New Features

  • Enhanced Single Sign-On (SSO) functionality with support for asynchronous context management.
  • Transition from tox to poe for running tests, streamlining the testing process.

• Bug Fixes

  • Improved handling of potential race conditions in SSO provider interactions.

• Documentation

  • Updated CONTRIBUTING.md to remove redundant test instructions and simplify contributor guidelines.
  • Modifications to various documentation files to reflect changes in SSO function implementations.

• Chores

  • Updated configuration files to remove tox dependency and include typing-extensions.

• Tests

  • Added new tests for race condition scenarios in SSO management and integrated security warnings in existing tests.