[wpimath] Exit early when parameterizing malformed spline (#6827)

Currently, a max iteration heuristic is used to determine when a spline
is malformed. Instead, we can report a failure immediately if dx and dy
are too small, because the heading won't be accurate either.

Fixes #6826.

wpimath/src/test/java/edu/wpi/first/math/spline/CubicHermiteSplineTest.java

@@ -36,7 +36,7 @@ class CubicHermiteSplineTest {
 
     var poses = new ArrayList<PoseWithCurvature>();
 
-    poses.add(splines[0].getPoint(0.0));
+    poses.add(splines[0].getPoint(0.0).get());
 
     for (var spline : splines) {
       poses.addAll(SplineParameterizer.parameterize(spline));