improve OpenTelemetry config

[zeitlinger]

• configure OpenTelemetry via opentelemetry-sdk-extension-autoconfigure
• use opentelemetry-micrometer-1.5 bridge
• the change is not fully backwards compatible, which could be improving by having new auto config classes - should be discussed
• all spring config options are still respected, both providing beans (e.g. for span filtering) and application properties
• if the user does not configure settings explicitly in application properties, then the SDK auto-configuration is used, for example you can either use management.tracing.propagation or otel.propagators - not sure if this can be surprising
• both sdk autoconfig and opentelemetry-micrometer-1.5 are alpha in otel, but haven't had any incompatible changes in the last months - I'll ask about it in the Java SIG

[pivotal-cla]

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[jonatan-ivanov]

I'm not sure a stable version of Boot should depend on something that is unstable.
Also, right now upgrading OTel to anything higher than 1.20.1 will break baggage propagation in Micrometer Tracing.

[jonatan-ivanov]

I think this should be auto-configured by OpenTelemetry I might be mistaken but I think they do. Also, Micrometer has an OTLP registry so if you want an OTLP output, you can use that (its auto-configured).

[wilkinsona]

Thanks for the proposal, @zeitlinger. Unfortunately, moving to an OpenTelemetry alpha is a non-starter. We'd also like to let other related changes settle before considering any further changes in this area. Those changes are coming in Micrometer, Micrometer Tracing and #34508 and should all be available in 3.1.0-M2 that is to be released later this month.