[scipy] Fix users of SciPy to prevent test failures under SciPy 1.13.

Release notes: https://docs.scipy.org/doc/scipy-1.13.0/release/1.13.0-notes.html

PiperOrigin-RevId: 657270964

tensorflow_probability/python/distributions/student_t_test.py

@@ -704,11 +704,11 @@ def testStdtrGradient(self):
 
     err = self.compute_max_gradient_error(
         lambda z: stdtr(z, t), [df], delta=1e-5)
-    self.assertLess(err, 2e-10)
+    self.assertLess(err, 3e-10)
 
     err = self.compute_max_gradient_error(
         lambda z: stdtr(df, z), [t], delta=1e-5)
-    self.assertLess(err, 7e-11)
+    self.assertLess(err, 2e-10)
 
   @parameterized.parameters(np.float32, np.float64)
   @test_util.numpy_disable_gradient_test