Stop using brotli #8118

Problem Statement

Brotli is only half-supported by Google anyway, and appears "somewhat underspecified".

The python Brotli package (which builds on C libraries) had an RCE in it till 1.2.0.
There is some reason to think this might not be the last security problem in that package.

sentry-python is, AFAICT, the only sentry SDK that actually uses brotli (when it is available).

Getting rid of this would (eventually) allow for sentry-server / relay to be able to stop accepting brotli and not be affected by its problems.

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disclosure: I'm the maintainer of a Sentry-compatible Error Tracker who's quite eager to be able to drop brotli support himself.