SpringBoot Add property to configure base time unit for Micrometer OTLP registry

Micrometer added a new property to its OTLP registry to enable configuring the base time unit, see: https://github.com/micrometer-metrics/micrometer/issues/3870. This should be released in 1.12.0-M1 (already available in 1.12.0-SNAPSHOT).

We should add property support for this in Boot too. Also related: https://github.com/spring-projects/spring-boot/issues/36188

Comment From: snicoll

Superseded by PR #36393