Previously, MeterRegistryPostProcessor would trigger the creation of all
meter binders and meter registry customizers before applying the
customizers and calling the binders. In some situations with complex
dependency graphs where the creation of a binder and the injection of
its dependencies inadvertently triggered some meter binding, this
could result in meters being bound before the registry had been
customized.
This commit reworks MeterRegistryPostProcessor and MeterRegistryConfigurer
to defer the retrieval of registry customizers and meter binders until
just before they are needed. As a result, customizers are now retrieved
and applied before the binders are retrieved.
Closes gh-15483
33fb1fa9a3