[build] Test each example in a new environment (wpilibsuite#5662)

In C++ each example is a separate source set, but in Java they were one source set and tested as one with the test task. Example-specific test tasks exist for Java, but they weren't used.
This modifies the test task to exclude the example tests, instead depending on each example's test task. The advantage of this is that each example is tested in a separate environment, so leftover state from one example isn't carried over.

wpilibjExamples/build.gradle

@@ -11,20 +11,6 @@ ext {
 
 apply from: "${rootDir}/shared/opencv.gradle"
 
-test {
-    useJUnitPlatform()
-    systemProperty 'junit.jupiter.extensions.autodetection.enabled', 'true'
-    testLogging {
-        events "failed"
-        exceptionFormat "full"
-    }
-    finalizedBy jacocoTestReport
-}
-
-if (project.hasProperty('onlylinuxathena') || project.hasProperty('onlylinuxarm32') || project.hasProperty('onlylinuxarm64') || project.hasProperty('onlywindowsarm64')) {
-    test.enabled = false
-}
-
 dependencies {
     implementation project(':wpilibj')
     implementation project(':apriltag')
@@ -197,6 +183,10 @@ model {
                                         includeTestsMatching("edu.wpi.first.wpilibj.examples.${entry.foldername}.*")
                                         setFailOnNoMatchingTests(false)
                                     }
+                                    test.filter {
+                                        excludeTestsMatching("edu.wpi.first.wpilibj.examples.${entry.foldername}.*")
+                                        setFailOnNoMatchingTests(false)
+                                    }
                                     testTask.classpath = sourceSets.test.runtimeClasspath
                                     testTask.dependsOn it.tasks.install
 
@@ -209,6 +199,11 @@ model {
                                     testTask.environment 'LD_LIBRARY_PATH', filePath
                                     testTask.environment 'DYLD_LIBRARY_PATH', filePath
                                     testTask.workingDir filePath
+
+                                    if (project.hasProperty('onlylinuxathena') || project.hasProperty('onlylinuxarm32') || project.hasProperty('onlylinuxarm64') || project.hasProperty('onlywindowsarm64')) {
+                                        testTask.enabled = false
+                                    }
+                                    test.dependsOn(testTask)
                                 }
                             }