[canvaskit] Don't bundle an embedded font

[harryterkelsen]

This removes the embedded font in CanvasKit. Since we always provide Roboto font, this is not required.

With this change, we remove 69.9 kb from the gzipped canvaskit.wasm (from 2296455 bytes to 2224892 bytes).

Fixes flutter/flutter#112397

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• I read the Contributor Guide and followed the process outlined there for submitting PRs.
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  writing and running engine tests.
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• All existing and new tests are passing.

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[yjbanov]