gh-36143: Fix two "Computational Math.." book doctests
    
Nothing interesting here, just two minor tweaks that are needed probably
due to a giac upgrade.
    
URL: #36143
Reported by: Michael Orlitzky
Reviewer(s): Kwankyu Lee, Michael Orlitzky

Author: Release Manager

src/sage/tests/books/computational-mathematics-with-sagemath/integration_doctest.py

@@ -253,7 +253,7 @@
 Sage example in ./integration.tex, line 1363::
 
   sage: t, y = var('t, y')
-  sage: desolve_rk4(t*y*(2-y), y, ics=[0,1], end_points=[0, 1], step=0.5)
+  sage: desolve_rk4(t*y*(2-y), y, ics=[0,1], end_points=[0, 1], step=0.5)  # abs tol 1e-12
   [[0, 1], [0.5, 1.12419127424558], [1.0, 1.461590162288825]]
 
 Sage example in ./integration.tex, line 1399::

src/sage/tests/books/computational-mathematics-with-sagemath/recequadiff_doctest.py

@@ -56,9 +56,15 @@
 
 Sage example in ./recequadiff.tex, line 459::
 
-  sage: desolve(y == x*diff(y,x)-diff(y,x)^2, y,
-  ....:         contrib_ode=True, show_method=True)
-  [[y(x) == -_C^2 + _C*x, y(x) == 1/4*x^2], 'clairault']
+  sage: diffeq = y == x*diff(y,x)-diff(y,x)^2
+  sage: solution,method = desolve(diffeq,
+  ....:                           y,
+  ....:                           contrib_ode=True,
+  ....:                           show_method=True)
+  sage: solution
+  [y(x) == -_C^2 + _C*x, y(x) == 1/4*x^2]
+  sage: method in ["clairaut", "clairault"]
+  True
 
 Sage example in ./recequadiff.tex, line 487::