[scipy] Fix test failures under SciPy 1.14.

This change updates code that fails under SciPy 1.14.

Scipy 1.14.0 release notes: https://docs.scipy.org/doc/scipy/release/1.14.0-notes.html#backwards-incompatible-changes

PiperOrigin-RevId: 747886518

Author: hawkinsp

tensorflow_probability/python/distributions/two_piece_student_t_test.py

@@ -276,7 +276,7 @@ def testSurvivalFunction(self):
         sf,
         expected_sf,
         atol=0.,
-        rtol=1e-6 if self.dtype == np.float32 else 5e-11)
+        rtol=2e-6 if self.dtype == np.float32 else 5e-11)
 
   def testQuantile(self):
     dist = self.make_two_piece_student_ts()