Remove old optics-core patch

The latest Hackage release, optics-core-0.3, supports 8.10 and HEAD.

patches/optics-core-0.2.patch

-diff --git a/src/Optics/Internal/Optic/Subtyping.hs b/src/Optics/Internal/Optic/Subtyping.hs
-index c0c8648..e6c4938 100644
---- a/src/Optics/Internal/Optic/Subtyping.hs
-+++ b/src/Optics/Internal/Optic/Subtyping.hs
-@@ -31,7 +31,7 @@ instance {-# OVERLAPPABLE #-} TypeError ('ShowType k
-                                          ':<>: 'Text " cannot be used as "
-                                          ':<>: 'ShowType l
-                                         ) => Is k l where
--  implies = error "unreachable"
-+  implies _ _ = error "unreachable"
- 
- -- | Every kind of optic can be used as itself.
- instance Is k k where