fix(confluent): temporarily cap confluent muzzle version

A recent update in the confluent schema registry introduced
jetty-versions which do not exist (9.4.59).  There's an upstream PR to
fix the issue
(confluentinc/kafka-connect-storage-common#468)
but while the longer term solution is pursued we are unblocking muzzle
tests/main.

Author: tabgok

dd-java-agent/instrumentation/confluent-schema-registry/confluent-schema-registry-4.1/build.gradle

@@ -6,6 +6,9 @@ muzzle {
     group = "io.confluent"
     module = "kafka-schema-registry-client"
     versions = "[4.1.0,)"
+    // broken POMs: depend on non-existent org.eclipse.jetty:jetty-bom:9.4.59
+    // can be fixed after https://github.com/confluentinc/kafka-connect-storage-common/issues/468 is resolved
+    skipVersions += ['7.4.14', '7.5.13', '7.6.10', '7.7.8', '7.8.7']
     excludeDependency "org.codehaus.jackson:jackson-mapper-asl" // missing on some releases
     assertInverse = true
   }