Errors should not be logged at the debug level

[AaldertVanWijk-TomTom]

Discussed in micronaut-projects/micronaut-core#7355

We had a serialization issue in the code that caused Micronaut to return a partially serialized object with a status of 200 (something I consider wrong in and of itself)

Part of what made this hard to find and debug (and prevents our monitoring reacting on error logs) is that this pretty severe error is deemed only worth printing when the log level is set to debug
This seems like a bad choice to me. and something that should be rectified.

micronaut-servlet/servlet-core/src/main/java/io/micronaut/servlet/http/ServletHttpHandler.java

Line 521 in 5a32cab

if (LOG.isDebugEnabled()) {