Enable sisyphus to recover from bad DNS without restart

[jkeljo]

Proposed change

If the initial attempt to contact the table fails outright, the sisyphus integration would throw PlatformNotReady forevermore. This PR fixes it so that each time we attempt to initialize the platform, it will make a new attempt to connect.

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

Additional information

The change to DNS settings around 0.97.2 (https://community.home-assistant.io/t/name-resolution-problem-since-0-97-2/132201/43) revealed this issue and provided an opportunity for testing. With this PR applied to my local instance, I tested as follows:

1. Start HA with incorrect DNS settings
2. Observe that the sisyphus integration reports not ready
3. Run ha dns options to set the correct DNS settings
4. Observe that the sisyphus integration starts successfully on the next retry

• This PR fixes or closes issue: fixes #
• This PR is related to issue:
• Link to documentation pull request:

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)
• Tests have been added to verify that the new code works.

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

• Documentation added/updated for www.home-assistant.io

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

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

The integration reached or maintains the following Integration Quality Scale:

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[MartinHjelmare]

Looks good!