remove auth_frac_op lemmas

They were the only _frac_ lemmas for these libraries, everything else is written as _dfrac_. The _dfrac_ lemmas are general enough to cover the frac case, so no reason to have these 3 specific lemmas (and not the dozens of others, corresponding to the dozens of other _dfrac_ lemmas) -- it is more consistent to just remove these few outliers.

The only user of these lemmas that I found is GPFSL, and just using the _dfrac_ lemma instead works fine there.

iris/algebra/lib/gmap_view.v

@@ -180,10 +180,6 @@ Section lemmas.
     gmap_view_auth (dp ⋅ dq) m ≡
     gmap_view_auth dp m ⋅ gmap_view_auth dq m.
   Proof. by rewrite /gmap_view_auth view_auth_dfrac_op. Qed.
-  Lemma gmap_view_auth_frac_op p q m :
-    gmap_view_auth (DfracOwn (p + q)) m ≡
-    gmap_view_auth (DfracOwn p) m ⋅ gmap_view_auth (DfracOwn q) m.
-  Proof. by rewrite /gmap_view_auth view_auth_frac_op. Qed.
   Global Instance gmap_view_auth_dfrac_is_op dq dq1 dq2 m :
     IsOp dq dq1 dq2 → IsOp' (gmap_view_auth dq m) (gmap_view_auth dq1 m) (gmap_view_auth dq2 m).
   Proof. rewrite /gmap_view_auth. apply _. Qed.