[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>

go.sum

@@ -491,8 +491,20 @@ go.mongodb.org/mongo-driver v1.17.3 h1:TQyXhnsWfWtgAhMtOgtYHMTkZIfBTpMTsMnd9ZBeH
 go.mongodb.org/mongo-driver v1.17.3/go.mod h1:Hy04i7O2kC4RS06ZrhPRqj/u4DTYkFDAAccj+rVKqgQ=
 go.opentelemetry.io/auto/sdk v1.1.0 h1:cH53jehLUN6UFLY71z+NDOiNJqDdPRaXzTel0sJySYA=
 go.opentelemetry.io/auto/sdk v1.1.0/go.mod h1:3wSPjt5PWp2RhlCcmmOial7AvC4DQqZb7a7wCow3W8A=
+go.opentelemetry.io/contrib/bridges/prometheus v0.60.0 h1:x7sPooQCwSg27SjtQee8GyIIRTQcF4s7eSkac6F2+VA=
+go.opentelemetry.io/contrib/bridges/prometheus v0.60.0/go.mod h1:4K5UXgiHxV484efGs42ejD7E2J/sIlepYgdGoPXe7hE=
+go.opentelemetry.io/contrib/exporters/autoexport v0.60.0 h1:GuQXpvSXNjpswpweIem84U9BNauqHHi2w1GtNAalvpM=
+go.opentelemetry.io/contrib/exporters/autoexport v0.60.0/go.mod h1:CkmxekdHco4d7thFJNPQ7Mby4jMBgZUclnrxT4e+ryk=
 go.opentelemetry.io/otel v1.35.0 h1:xKWKPxrxB6OtMCbmMY021CqC45J+3Onta9MqjhnusiQ=
 go.opentelemetry.io/otel v1.35.0/go.mod h1:UEqy8Zp11hpkUrL73gSlELM0DupHoiq72dR+Zqel/+Y=
+go.opentelemetry.io/otel/exporters/otlp/otlplog/otlploggrpc v0.11.0 h1:HMUytBT3uGhPKYY/u/G5MR9itrlSO2SMOsSD3Tk3k7A=
+go.opentelemetry.io/otel/exporters/otlp/otlplog/otlploggrpc v0.11.0/go.mod h1:hdDXsiNLmdW/9BF2jQpnHHlhFajpWCEYfM6e5m2OAZg=
+go.opentelemetry.io/otel/exporters/otlp/otlplog/otlploghttp v0.11.0 h1:C/Wi2F8wEmbxJ9Kuzw/nhP+Z9XaHYMkyDmXy6yR2cjw=
+go.opentelemetry.io/otel/exporters/otlp/otlplog/otlploghttp v0.11.0/go.mod h1:0Lr9vmGKzadCTgsiBydxr6GEZ8SsZ7Ks53LzjWG5Ar4=
+go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc v1.35.0 h1:QcFwRrZLc82r8wODjvyCbP7Ifp3UANaBSmhDSFjnqSc=
+go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc v1.35.0/go.mod h1:CXIWhUomyWBG/oY2/r/kLp6K/cmx9e/7DLpBuuGdLCA=
+go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp v1.35.0 h1:0NIXxOCFx+SKbhCVxwl3ETG8ClLPAa0KuKV6p3yhxP8=
+go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp v1.35.0/go.mod h1:ChZSJbbfbl/DcRZNc9Gqh6DYGlfjw4PvO1pEOZH1ZsE=
 go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.35.0 h1:1fTNlAIJZGWLP5FVu0fikVry1IsiUnXjf7QFvoNN3Xw=
 go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.35.0/go.mod h1:zjPK58DtkqQFn+YUMbx0M2XV3QgKU0gS9LeGohREyK4=
 go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.35.0 h1:m639+BofXTvcY1q8CGs4ItwQarYtJPOWmVobfM1HpVI=
@@ -501,10 +513,20 @@ go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp v1.35.0 h1:xJ2qH
 go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp v1.35.0/go.mod h1:u5BF1xyjstDowA1R5QAO9JHzqK+ublenEW/dyqTjBVk=
 go.opentelemetry.io/otel/exporters/prometheus v0.57.0 h1:AHh/lAP1BHrY5gBwk8ncc25FXWm/gmmY3BX258z5nuk=
 go.opentelemetry.io/otel/exporters/prometheus v0.57.0/go.mod h1:QpFWz1QxqevfjwzYdbMb4Y1NnlJvqSGwyuU0B4iuc9c=
+go.opentelemetry.io/otel/exporters/stdout/stdoutlog v0.11.0 h1:k6KdfZk72tVW/QVZf60xlDziDvYAePj5QHwoQvrB2m8=
+go.opentelemetry.io/otel/exporters/stdout/stdoutlog v0.11.0/go.mod h1:5Y3ZJLqzi/x/kYtrSrPSx7TFI/SGsL7q2kME027tH6I=
+go.opentelemetry.io/otel/exporters/stdout/stdoutmetric v1.35.0 h1:PB3Zrjs1sG1GBX51SXyTSoOTqcDglmsk7nT6tkKPb/k=
+go.opentelemetry.io/otel/exporters/stdout/stdoutmetric v1.35.0/go.mod h1:U2R3XyVPzn0WX7wOIypPuptulsMcPDPs/oiSVOMVnHY=
+go.opentelemetry.io/otel/exporters/stdout/stdouttrace v1.35.0 h1:T0Ec2E+3YZf5bgTNQVet8iTDW7oIk03tXHq+wkwIDnE=
+go.opentelemetry.io/otel/exporters/stdout/stdouttrace v1.35.0/go.mod h1:30v2gqH+vYGJsesLWFov8u47EpYTcIQcBjKpI6pJThg=
+go.opentelemetry.io/otel/log v0.11.0 h1:c24Hrlk5WJ8JWcwbQxdBqxZdOK7PcP/LFtOtwpDTe3Y=
+go.opentelemetry.io/otel/log v0.11.0/go.mod h1:U/sxQ83FPmT29trrifhQg+Zj2lo1/IPN1PF6RTFqdwc=
 go.opentelemetry.io/otel/metric v1.35.0 h1:0znxYu2SNyuMSQT4Y9WDWej0VpcsxkuklLa4/siN90M=
 go.opentelemetry.io/otel/metric v1.35.0/go.mod h1:nKVFgxBZ2fReX6IlyW28MgZojkoAkJGaE8CpgeAU3oE=
 go.opentelemetry.io/otel/sdk v1.35.0 h1:iPctf8iprVySXSKJffSS79eOjl9pvxV9ZqOWT0QejKY=
 go.opentelemetry.io/otel/sdk v1.35.0/go.mod h1:+ga1bZliga3DxJ3CQGg3updiaAJoNECOgJREo9KHGQg=
+go.opentelemetry.io/otel/sdk/log v0.11.0 h1:7bAOpjpGglWhdEzP8z0VXc4jObOiDEwr3IYbhBnjk2c=
+go.opentelemetry.io/otel/sdk/log v0.11.0/go.mod h1:dndLTxZbwBstZoqsJB3kGsRPkpAgaJrWfQg3lhlHFFY=
 go.opentelemetry.io/otel/sdk/metric v1.35.0 h1:1RriWBmCKgkeHEhM7a2uMjMUfP7MsOF5JpUCaEqEI9o=
 go.opentelemetry.io/otel/sdk/metric v1.35.0/go.mod h1:is6XYCUMpcKi+ZsOvfluY5YstFnhW0BidkR+gL+qN+w=
 go.opentelemetry.io/otel/trace v1.35.0 h1:dPpEfJu1sDIqruz7BHFG3c7528f6ddfSWfFDVt/xgMs=