fix: define filetypes for clang formatter explicitly

lua/plugins/none-ls.lua

@@ -9,7 +9,9 @@ return {
         null_ls.builtins.formatting.prettier,
         null_ls.builtins.formatting.black,
         null_ls.builtins.formatting.isort,
-				null_ls.builtins.formatting.clang_format,
+        null_ls.builtins.formatting.clang_format.with({
+          filetypes = { "c", "cpp", "objc", "objcpp", "cuda", "proto" },
+        }),
       },
     })