clean up convert-based fallbacks

fix https://github.com/SciML/LinearSolve.jl/actions/runs/5417914034/jobs/9849418672?pr=337#step:6:13263

Author: vpuri3

src/interface.jl

@@ -384,20 +384,11 @@ for pred in (
              :isposdef,
             )
     @eval function LinearAlgebra.$pred(L::AbstractSciMLOperator)
-        @warn """using convert-based fallback in $pred."""
+        @warn """using convert-based fallback in $($pred)."""
         $pred(convert(AbstractMatrix, L))
     end
 end
 
-for op in (
-           :sum,:prod
-          )
-    @eval function LinearAlgebra.$op(L::AbstractSciMLOperator; kwargs...)
-        @warn """using convert-based fallback in $op."""
-        $op(convert(AbstractMatrix, L); kwargs...)
-    end
-end
-
 function LinearAlgebra.mul!(v::AbstractArray, L::AbstractSciMLOperator, u::AbstractArray)
     @warn """using convert-based fallback in mul!."""
     mul!(v, convert(AbstractMatrix, L), u)