[3.15] gh-140036: Test modulo and divmod of pure Python Decimal in unbounded contexts (GH-160482) (#160808)

gh-140036: Test modulo and divmod of pure Python Decimal in unbounded contexts (GH-160482)
(cherry picked from commit e7ab898)

Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>

Author: miss-islington

Lib/test/test_decimal.py

@@ -4721,6 +4721,16 @@ def test_divide_unbound_context(self):
             x = self.decimal.Decimal('1')
             y = x // 1  # should be fast
 
+    def test_modulo_unbound_context(self):
+        with self.unbound_context() as c:
+            x = self.decimal.Decimal('1')
+            y = x % 1  # should be fast
+
+    def test_divmod_unbound_context(self):
+        with self.unbound_context() as c:
+            x = self.decimal.Decimal('1')
+            y = divmod(x, 1)  # should be fast
+
     def test_remainder_near(self):
         L = 1000
         limit = sys.get_int_max_str_digits()