update to Gradle 7.4

- use updated testing plugin to work with new Gradle version

build.gradle

@@ -6,7 +6,7 @@ buildscript {
         }
     }
     dependencies {
-        classpath 'org.jastadd.preprocessor:testing:0.2.13-28'
+        classpath 'org.jastadd.preprocessor:testing:0.2.13-30'
     }
 }
 
@@ -240,7 +240,6 @@ task compileDefaultNamesTest(type: RelastTest) {
         inputFiles = [file('src/test/jastadd/relations/Relations.relast')]
         grammarName = 'src/test/jastadd/relations/Relations3'
         useJastAddNames = false
-        verbose = true
         noResolverHelper = true
     }
     jastadd {
@@ -370,7 +369,6 @@ task compileSerializerDefaultNamesTest(type: RelastTest) {
         grammarName = 'src/test/jastadd/serializer-names/Serializer'
         serializer = 'jackson'
         useJastAddNames = false
-        verbose = true
         noResolverHelper = true
     }
     jastadd {

gradle/wrapper/gradle-wrapper.properties

 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-6.8.1-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-7.4-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists