[wpilib] Deprecate getInstance() in favor of static functions (#3440)

Co-authored-by: Noam Zaks <imnoamzaks@gmail.com>

wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/GyroTest.java

@@ -30,7 +30,7 @@ public class GyroTest extends AbstractComsSetup {
   @Before
   public void setUp() {
     logger.fine("Setup: TiltPan camera");
-    m_tpcam = TestBench.getInstance().getTiltPanCam();
+    m_tpcam = TestBench.getTiltPanCam();
     m_tpcam.setup();
   }