reduce getCircuitBreakerManager calls in SearchHandler

It's a little bit subjective but I think having just one call would help with code reading and marginally one less method call is also not unhelpful. Small pull request with proposed change opened.

existing code: https://github.com/apache/lucene-solr/blob/releases/lucene-solr/8.9.0/solr/core/src/java/org/apache/solr/handler/component/SearchHandler.java#L303-L325