gh-38689: Fix tests with singular 4.4.0p3

    
Fuzz some tests to make then pass with singular>=4.4.0p3, which returns
different Gröbner bases in some cases
    
URL: #38689
Reported by: Antonio Rojas
Reviewer(s): Antonio Rojas, Michael Orlitzky

src/sage/libs/singular/option.pyx

@@ -20,15 +20,17 @@ By default, tail reductions are performed::
     sage: from sage.libs.singular.option import opt, opt_ctx
     sage: opt['red_tail']
     True
-    sage: std(I)[-1]
+    sage: red = std(I)[-1]; red
     d^2*e^6 + 28*b*c*d + ...
 
 If we don't want this, we can create an option context, which disables
 this::
 
     sage: with opt_ctx(red_tail=False, red_sb=False):
-    ....:    std(I)[-1]
-    d^2*e^6 + 8*c^3 + ...
+    ....:    notred = std(I)[-1]; notred
+    d^2*e^6 + ...
+    sage: len(list(red)) < len(list(notred))
+    True
 
 However, this does not affect the global state::
 

src/sage/rings/polynomial/multi_polynomial_ideal.py

@@ -176,7 +176,7 @@
     The Groebner basis modulo any product of the prime factors is also non-trivial::
 
         sage: I.change_ring(P.change_ring(IntegerModRing(2 * 7))).groebner_basis()
-        [x + 9*y + 13*z, y^2 + 3*y, y*z + 7*y + 6, 2*y + 6, z^2 + 3, 2*z + 10]
+        [x + ..., y^2 + 3*y, y*z + 7*y + 6, 2*y + 6, z^2 + 3, 2*z + 10]
 
     Modulo any other prime the Groebner basis is trivial so there are
     no other solutions. For example::