Remove deprecated constructor and dropwizard dependency

The Ganglia registry does not use Dropwizard anymore. This constructor was left only for backwards compatibility.

Closes gh-3016

implementations/micrometer-registry-ganglia/build.gradle

@@ -4,8 +4,5 @@ dependencies {
     api 'info.ganglia.gmetric4j:gmetric4j'
     implementation 'org.slf4j:slf4j-api'
 
-    // Deprecated constructor references this which is otherwise unused.
-    compileOnly 'io.dropwizard.metrics:metrics-core'
-
     testImplementation project(':micrometer-test')
 }

implementations/micrometer-registry-ganglia/src/main/java/io/micrometer/ganglia/GangliaMeterRegistry.java

@@ -15,7 +15,6 @@
  */
 package io.micrometer.ganglia;
 
-import com.codahale.metrics.MetricRegistry;
 import info.ganglia.gmetric4j.gmetric.GMetric;
 import info.ganglia.gmetric4j.gmetric.GMetricSlope;
 import info.ganglia.gmetric4j.gmetric.GMetricType;
@@ -84,20 +83,6 @@ private GangliaMeterRegistry(GangliaConfig config, Clock clock, HierarchicalName
         }
     }
 
-    /**
-     * @param config         The registry configuration.
-     * @param clock          The clock to use for timings.
-     * @param nameMapper     The name mapper to use in converting dimensional metrics to hierarchical names.
-     * @param metricRegistry Ignored as of Micrometer 1.1.0.
-     * @deprecated The Ganglia registry no longer uses Dropwizard as of Micrometer 1.1.0, because Dropwizard
-     * dropped support for Ganglia in its 4.0.0 release. Use {@link #builder(GangliaConfig)} instead.
-     */
-    @SuppressWarnings("unused")
-    @Deprecated
-    public GangliaMeterRegistry(GangliaConfig config, Clock clock, HierarchicalNameMapper nameMapper, MetricRegistry metricRegistry) {
-        this(config, clock, nameMapper);
-    }
-
     public static Builder builder(GangliaConfig config) {
         return new Builder(config);
     }