Manifest v3 compatibility

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Changes:

• Host permissions have moved to host_permissions
• The *://*/* permission was moved from optional_permissions to host_permissions

https://developer.chrome.com/docs/extensions/mv3/intro/mv3-migration/#host-permissions

I'll fix this as part of

• https://github.com/pixiebrix/pixiebrix-extension/issues/287

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Optional permissions are still not available/finalized in MV3, so this module can't support them yet.

https://groups.google.com/a/chromium.org/g/chromium-extensions/c/E-VTpwtSYxM

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It does not support host_permissions yet

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Fixed