Use string.Concat instead of string.Join

Proprietary

Replace string.Join("", args) with string.Concat(args).

OpenRewrite.Recipes.CSharp.CodeQuality.Performance.UseStringConcatInsteadOfJoin

mod run . --recipe=OpenRewrite.Recipes.CSharp.CodeQuality.Performance.UseStringConcatInsteadOfJoin

Install it once, then run it on every repository under the current directory. New to the Moderne CLI? Set it up.