A half-decade ago, Forum:Removing ages from actor pages established that we would remove actors ages and start again, this time using sources acceptable to (what became) T:VS. So, while IMDb and Wikipedia are out, as Shambala108 says, the Guardian would be okay. (Unless the valid source was directly quoting the actor, in which case T:NO SELF REF would disallow it, since actors regularly lie about their ages to the press.)
Of course, in this case, we have no source beyond the Guardian. There's no guarantee that they didn't simply go to IMDb and snatch the date from there. But the point is that we have some reasonably credible publication (i.e. not a publicly edited site) making the claim. And we leave it up to the reader to decide if the Guardian is a good enough source for their purposes.