Remove usage of the tracing crate

[tomaka]

Close #46

As explained in the issue, despite having tried it for a long time I don't actually see the point of this crate. Spans are confusing and quite useless, and there's no traces sink that works well apart from the same ones as log (stdout and writing to files).

[github-actions]

twiggy diff report

Difference in .wasm size before and after this pull request.

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