Remove unnecessary test results directory configuration

Commit eec183ef configured the
Artifactory Gradle task in the Default Job of the Bamboo build plan for
the Spring Framework (SPR-PUB) to use the following Gradle-friendly test
results directory pattern: `**/build/test-results/**/*.xml`.

That change made the existing custom configuration of the test results
directory in the common Gradle `test` task obsolete.

build.gradle

@@ -146,7 +146,6 @@ configure(allprojects) { project ->
 		// classes with the "$" pattern; otherwise, using -Dtest.single=MyTests to
 		// run MyTests by itself will fail if MyTests contains any inner classes.
 		exclude(["**/Abstract*.class", '**/*$*'])
-		reports.junitXml.setDestination(file("$buildDir/test-results"))
 	}
 
 	checkstyle {