[chore] Simplify the OTEL setup (#4110)

# Description

This simplifies our OTEL setup by:

* Getting rid of some deprecated things.
* Using `autoexport` and letting things get configured by the `OTEL_` environment variables.
* Removing all the unnecessary config options.

## Checklist

Please put an x inside each checkbox to indicate that you've read and followed it: `[ ]` -> `[x]`

If this is a documentation change, only the first checkbox must be filled (you can delete the others if you want).

- [x] I/we have read the [GoToSocial contribution guidelines](https://codeberg.org/superseriousbusiness/gotosocial/src/branch/main/CONTRIBUTING.md).
- [x] I/we have discussed the proposed changes already, either in an issue on the repository, or in the Matrix chat.
- [x] I/we have not leveraged AI to create the proposed changes.
- [x] I/we have performed a self-review of added code.
- [x] 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.
- [x] I/we have made any necessary changes to documentation.
- [ ] I/we have added tests that cover new code.
- [x] I/we have run tests and they pass locally with the changes.
- [x] I/we have run `go fmt ./...` and `golangci-lint run`.

Reviewed-on: https://codeberg.org/superseriousbusiness/gotosocial/pulls/4110
Reviewed-by: tobi <kipvandenbos@noreply.codeberg.org>
Co-authored-by: Daenney <daenney@noreply.codeberg.org>
Co-committed-by: Daenney <daenney@noreply.codeberg.org>

1 files changed, 22 insertions, 0 deletions

diff --git a/vendor/go.opentelemetry.io/contrib/bridges/prometheus/doc.go b/vendor/go.opentelemetry.io/contrib/bridges/prometheus/doc.go
new file mode 100644
index 000000000..44145a103
--- /dev/null
+++ b/vendor/go.opentelemetry.io/contrib/bridges/prometheus/doc.go
@@ -0,0 +1,22 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+// Package prometheus provides a bridge from Prometheus to OpenTelemetry.
+//
+// The Prometheus Bridge allows using the [Prometheus Golang client library]
+// with the OpenTelemetry SDK. This enables prometheus instrumentation libraries
+// to be used with OpenTelemetry exporters, including OTLP.
+//
+// Prometheus histograms are translated to OpenTelemetry exponential histograms
+// when native histograms are enabled in the Prometheus client. To enable
+// Prometheus native histograms, set the (currently experimental) NativeHistogram...
+// options of the prometheus [HistogramOpts] when creating prometheus histograms.
+//
+// While the Prometheus Bridge has some overhead, it can significantly reduce the
+// combined overall CPU and Memory footprint when sending to an OpenTelemetry
+// Collector. See the [benchmarks] for more details.
+//
+// [Prometheus Golang client library]: https://github.com/prometheus/client_golang
+// [HistogramOpts]: https://pkg.go.dev/github.com/prometheus/client_golang/prometheus#HistogramOpts
+// [benchmarks]: https://github.com/open-telemetry/opentelemetry-go-contrib/blob/main/bridges/prometheus/BENCHMARKS.md
+package prometheus // import "go.opentelemetry.io/contrib/bridges/prometheus"