ref(anyhow): Disable anyhow's backtrace feature

[sugar700]

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Since anyhow 1.0.77, backtrace feature is not needed for Rust 1.65+ (https://github.com/dtolnay/anyhow/releases/tag/1.0.77). Because sentry has a higher MSRV than that, it's no longer necessary to enable this feature.

[Swatinem]

It might not be necessary, but I doubt it hurts to keep it?

I would have to take a closer look at this in any case.