gh-124040: simplify two hypot tests

One-argument form is enough to test L2636 and compare computed
values exactly.

Author: skirpichev

Lib/test/test_math.py

@@ -809,8 +809,8 @@ def testHypot(self):
         # Test allowable types (those with __float__)
         self.assertEqual(hypot(12.0, 5.0), 13.0)
         self.assertEqual(hypot(12, 5), 13)
-        self.assertEqual(hypot(1, -1), math.sqrt(2))
-        self.assertEqual(hypot(1, FloatLike(-1.)), math.sqrt(2))
+        self.assertEqual(hypot(-1), 1.0)
+        self.assertEqual(hypot(FloatLike(-1.)), 1.0)
         self.assertEqual(hypot(Decimal(12), Decimal(5)), 13)
         self.assertEqual(hypot(Fraction(12, 32), Fraction(5, 32)), Fraction(13, 32))
         self.assertEqual(hypot(bool(1), bool(0), bool(1), bool(1)), math.sqrt(3))