Avoid prematurely triggering logger initialization

The class Setting holds a static reference to a deprecation logger
instance. When the class initializer for Setting runs, it starts
triggering log4j initialization. There is a chain of initializations
from InternalSettingsPreparer to Environment to Setting that triggers
this initialization before log4j configuration has occurred. This commit
modifies this initialization so that initialization is not done eagerly.

Relates #20170

core/src/main/java/org/elasticsearch/common/settings/Setting.java

@@ -107,9 +107,6 @@ public class Setting<T> extends ToXContentToBytes {
         IndexScope
     }
 
-    private static final ESLogger logger = Loggers.getLogger(Setting.class);
-    private static final DeprecationLogger deprecationLogger = new DeprecationLogger(logger);
-
     private final Key key;
     protected final Function<Settings, String> defaultValue;
     @Nullable
@@ -322,6 +319,7 @@ public class Setting<T> extends ToXContentToBytes {
         // They're using the setting, so we need to tell them to stop
         if (this.isDeprecated() && this.exists(settings)) {
             // It would be convenient to show its replacement key, but replacement is often not so simple
+            final DeprecationLogger deprecationLogger = new DeprecationLogger(Loggers.getLogger(getClass()));
             deprecationLogger.deprecated("[{}] setting was deprecated in Elasticsearch and it will be removed in a future release! " +
                     "See the breaking changes lists in the documentation for details", getKey());
         }