app: delete 2 unused imports

Author: stephengold

src/test/java/testjoltjni/app/performancetest/CharacterVirtualScene.java

@@ -25,7 +25,6 @@ of this software and associated documentation files (the "Software"), to deal
 import com.github.stephengold.joltjni.readonly.*;
 import static com.github.stephengold.joltjni.Jolt.*;
 import static com.github.stephengold.joltjni.operator.Op.*;
-import static com.github.stephengold.joltjni.std.Std.*;
 import java.util.*;
 
 /**

src/test/java/testjoltjni/app/samples/ShapeCreator.java

@@ -23,7 +23,6 @@ of this software and associated documentation files (the "Software"), to deal
 import com.github.stephengold.joltjni.*;
 import com.github.stephengold.joltjni.operator.Op;
 import static com.github.stephengold.joltjni.Jolt.*;
-import static com.github.stephengold.joltjni.std.Std.*;
 /**
  * A line-for-line Java translation of the {@code ShapeCreator} namespace.
  * <p>