[feature] Log OTEL internal logs

[Tsuribori]

Description

Currently the internal logs of the OTEL library aren't logged making it hard to debug situations like #3117

The OTEL library expects a Logr logger to be passed to it so this pull request implements a Logr LogSink that logs through the existing logging mechanism.

When tracing is enabled this will produce logs like the following for example:

timestamp="14/08/2024 19:00:18.752" func=trace.(*TracerProvider).Tracer level=INFO name=github.com/uptrace/bun version="" schemaURL="" msg="Tracer created"
timestamp="14/08/2024 19:00:19.173" func=trace.(*TracerProvider).Tracer level=INFO name=github.com/superseriousbusiness/gotosocial/internal/tracing version=0.0.0-testrig schemaURL="" msg="Tracer created"
timestamp="14/08/2024 19:05:23.394" func=trace.(*batchSpanProcessor).exportSpans level=DEBUG count=2 total_dropped=0 msg="exporting spans"

Checklist

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• I/we have read the GoToSocial contribution guidelines.
• I/we have discussed the proposed changes already, either in an issue on the repository, or in the Matrix chat.
• I/we have not leveraged AI to create the proposed changes.
• I/we have performed a self-review of added code.
• I/we have written code that is legible and maintainable by others.
• I/we have commented the added code, particularly in hard-to-understand areas.
• I/we have made any necessary changes to documentation.
• I/we have added tests that cover new code.
• I/we have run tests and they pass locally with the changes.
• I/we have run go fmt ./... and golangci-lint run.

[daenney]

Please respect the import sorting, stdlib first, external in a second block.

[daenney]

This adds ogging output when tracing is enabled that's not necessarily useful to people under normal conditions.

I agree it's useful for debugging tracing issues, but I think we should put this behind a config flag that enables the internal tracing logger only when requested. Something like tracing-logger-enabled, to stick with the current naming conventions.

[NyaaaWhatsUpDoc]

honestly i was going to suggest maybe moving this into the tracing package itself so this code is only there when the build tag is enabled. are you good with me having a poke around on this branch @Tsuribori and maybe trying shifting it around?

[Tsuribori]

honestly i was going to suggest maybe moving this into the tracing package itself so this code is only there when the build tag is enabled. are you good with me having a poke around on this branch @Tsuribori and maybe trying shifting it around?

Sure

[daenney]

honestly i was going to suggest maybe moving this into the tracing package itself so this code is only there when the build tag is enabled. are you good with me having a poke around on this branch @Tsuribori and maybe trying shifting it around?

I think that's fine too, but I would still like to be able to run with tracing enabled but without additional logging by the tracer itself.