Trac #29963: Make geometry doctests ready for random seeds

This ticket makes
{{{
sage -t --long --random-seed=n src/sage/geometry/
}}}
pass for different values `n` than just `0` except for
`src/sage/geometry/hyperbolic_space/hyperbolic_geodesic.py`, which will
be taken care of by #29936.

URL: https://trac.sagemath.org/29963
Reported by: gh-kliem
Ticket author(s): Jonathan Kliem
Reviewer(s): Sébastien Labbé

src/sage/geometry/hyperbolic_space/hyperbolic_point.py

@@ -480,8 +480,8 @@ def symmetry_involution(self):
 
             sage: p = HyperbolicPlane().UHP().random_element()
             sage: A = p.symmetry_involution()
-            sage: A*p == p
-            True
+            sage: p.dist(A*p)  # abs tol 1e-10
+            0
 
             sage: A.preserves_orientation()
             True

src/sage/geometry/linear_expression.py

@@ -653,8 +653,8 @@ def random_element(self):
 
             sage: from sage.geometry.linear_expression import LinearExpressionModule
             sage: L.<x,y,z> = LinearExpressionModule(QQ)
-            sage: L.random_element()
-            -1/2*x - 1/95*y + 1/2*z - 12
+            sage: L.random_element() in L
+            True
         """
         A = self.ambient_module().random_element()
         b = self.base_ring().random_element()