Update stream integration for Python 3.9 which removed isAlive from threading in favor of is_alive

[ColinRobbins]

Proposed change

Update stream integration for Python 3.9 which removed isAlive from threading in favor of is_alive
https://bugs.python.org/iss

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New integration (thank you!)
• New feature (which adds functionality to an existing integration)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Example entry for configuration.yaml:

N/A

Additional information

N/A

Checklist

• The code change is tested and works locally.
• Local tests pass. Your PR cannot be merged unless tests pass
• There is no commented out code in this PR.
• I have followed the development checklist
• The code has been formatted using Black (black --fast homeassistant tests)
• [ N/A] Tests have been added to verify that the new code works.

If user exposed functionality or configuration variables are added/changed:

• [N/A] Documentation added/updated for www.home-assistant.io

If the code communicates with devices, web services, or third-party tools:

• [N/A] The manifest file has all fields filled out correctly.
  Updated and included derived files by running: python3 -m script.hassfest.
• [N/A] New or updated dependencies have been added to requirements_all.txt.
  Updated by running python3 -m script.gen_requirements_all.
• [N/A] Untested files have been added to .coveragerc.

The integration reached or maintains the following Integration Quality Scale:

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To help with the load of incoming pull requests:

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