Guess media type when cast is playing media without media type

[emontnemery]

Proposed change

Guess media type when cast is playing media without media type

Media type does not seem to be set when testing on a Google Nest Hub 2, while it's set when testing on other devices.

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
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• Breaking change (fix/feature causing existing functionality to break)
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• This PR fixes or closes issue: fixes #
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