Logstash information:

Please include the following information:

1. Logstash version (e.g. bin/logstash --version): [7.3.2,9.x]
2. Logstash installation source (e.g. built from source, with a package manager: DEB/RPM, expanded from tar or zip archive, docker): NA
3. How is Logstash being run (e.g. as a service/service manager: systemd, upstart, etc. Via command line, docker/kubernetes): NA

Steps to reproduce:

1. provide config.reload.interval and/or config.reload.automatic inside a pipeline defined in pipelines.yml, with values different than those specified in logstash.yml
2. observe that no error or warning occurs, but that the pipeline in question also doesn't respect the per-pipeline values. This is because it can't. Pipeline reloading is a function of the agent, and the individual pipelines are not aware of this value.

Fix notes:

In the real world, pipeline definitions can currently include this setting, so it would be a breaking change to simply remove it from the allow-list.

Instead, we should emit a deprecation log when it is provided as an override at the pipeline level, indicating that the per-pipeline value will be ignored.

We should also audit the other settings made pipeline-overridable in #11076