Solving with respect to a dummy variable behaves wrong

[pelegm]

Solving an equation which only involves x, with respect to y, gives a solution with respect to x:

sage: var('x,y')
(x, y)
sage: solve(x > 0, y)
[[x > 0]]

(Expected answer: for all y...)

It does not change if one adds y to the equation in a dummy way (like y*0).

Similarly, the following code:

solve(1>x*0, y)

returns [[]], where the expected result should probably be for all y. For the second example sympy returns True.

Component: symbolics

Keywords: solve, days79

Issue created by migration from https://trac.sagemath.org/ticket/21939