If you have a large rigid body and you consider forces acting on it, then it's useful to define not only the direction of a force (as a vector), but also where it acts, the line of action. The result will be different if you push a body with the same force and in the same direction, but applying the push in different places. The mathematical abstraction used for it in some textbooks is "a sliding vector". Then generally speaking the 3rd law as applied to rigid bodies pushing/pulling on each other will have the lines of action not only parallel, but also on the same line. That's why some textbooks talk about "the same line of action". In particular I expect engineering-minded textbooks use this phrasing more often, because lines of action arise due to practical concerns of figuring out movement and equilibrium of real-world bodies.
On the other hand, pure-physics textbooks often present Newton's laws in a very fundamental, basic formulation where we deal only with point particles. Then "lines of action" don't really make sense, because a force acting on a point always applies at the point, and all you need to specify is the direction. Then the 3rd law always includes the fact that the forces are parallel, but the "strong form" of the 3rd law includes also that they're collinear in the sense of being also parallel to the line between the points (and therefore actually coinciding with that line as vectors, because they have no other choice, because they apply at the points). Your confusion is due to interpreting "collinear" as "same line of action", in the rigid-body framework above. But in this point-particle framework, "collinear" is used to distinguish between forces that coincide with the line between the particles, and forces that don't (but are still parallel), and it's misleading to talk about "lines of action".
To sum up:
- Talking about forces between rigid bodies -- lines of action -- 3rd law implies that contact forces act on the same line of action, but it's not usually called "collinearity" (although technically correct)
- Talking about forces between point particles -- no "lines of action" -- 3rd law in weak form doesn't include collinearity, in strong form does, and the part to emphasize about it is the fact that the forces coincide with the line between the particles (that fact will make their contribution to angular momentum, and not only momentum, vanish).