Syntheses of Bis(aryloxo)halogenoytterbium(III) Complexes: [Yb(OAr)2X(THF)2] (X = Cl, Br, I; OAr = OC6H2–2,6‐tBu2–4‐R; R = H, Me, tBu) and the X‐Ray Crystal Structures of [Yb(OC6H2–2,6‐tBu2‐4‐Me)2I(THF)2] and [Yb(OC6H3‐2,6‐tBu2)2OH(THF)]2