Remove unnecessary fmt package & remove sentry_sentry auth arg

[jmeissen]

Hello, nice to see some activity in this repository!

I'm back again with another PR.

Marshal had the bright idea to :nicknames one of its packages fmt, which conflicts with the fmt package this library requires, so I replaced fmt with a format. Since the fmt library is only used once (to format that Auth header) and I think my suggested replacement is a bit more readable (maybe not the control-string tho :p), I removed the :depends-on as well in the asd-file.

Additionally, Sentry SDK - Authentication states sentry_secret to be effectively deprecated, so I removed it in the same commit from the Auth header since there's no sentry_secret referenced anywhere anymore. Also, the resulting value of sentry_secret would end up being NIL, which the docs whine about:

The sentry_secret must only be included if a secret key portion was contained in the DSN.

Lastly, an unrelated matter: I noticed sentry_version=5, while the docs state the sentry_version to be 7. My search efforts could not determine whether it affects anything, so I'm just giving a heads-up. Maybe you know if its wanted or not.

Thanks

[mmontone]

Thanks. I'm merging your pull request.

I know nothing about the sentry_version thing :)