color-eyre: Depends on removed backtrace features such that it can't be upgraded

[VorpalBlade]

Quoting https://github.com/rust-lang/backtrace-rs/releases/tag/0.3.72:

This release removes a lot of dead code. Some feature flags that haven't done anything in a long time are gone. If you depend on those features, Cargo's resolver will not update you to 0.3.72.

Color-eyre depends the removed gimli-symbolize feature. It would be good to get a new release on crates.io with this feature (that presumably doesn't do anything any more) removed. Currently this needlessly blocks upgrades.

I see that the flag is already removed from color-eyre on master, but that doesn't help us who publish our projects to crates.io

[yaahc]

working on this in #215