Revert implicit for Resource MonadError instance

MonadCancelThrow instance (which is required for the fixed attempt)
is already higher priority than this one. By leaving it implicit,
users will get an actionable deprecation instead of non-compiling code.

kernel/shared/src/main/scala/cats/effect/kernel/Resource.scala

@@ -1303,7 +1303,7 @@ private[effect] trait ResourceHOInstances3 extends ResourceHOInstances4 {
 
 private[effect] trait ResourceHOInstances4 extends ResourceHOInstances5 {
   @deprecated("Use MonadCancelThrow instances", "3.6.0")
-  def catsEffectMonadErrorForResource[F[_], E](
+  implicit def catsEffectMonadErrorForResource[F[_], E](
       implicit F0: MonadError[F, E]): MonadError[Resource[F, *], E] =
     new ResourceMonadError[F, E] {
       def F = F0