Track utilities generated by @apply

packages/tailwindcss/src/apply.ts

@@ -167,8 +167,13 @@ export function substituteAtApply(ast: AstNode[], designSystem: DesignSystem) {
           },
         })
 
+        let src = node.src
         let candidateAst = compiled.astNodes
 
+        walk(candidateAst, (node) => {
+          node.src = src
+        })
+
         // Collect the nodes to insert in place of the `@apply` rule. When a rule
         // was used, we want to insert its children instead of the rule because we
         // don't want the wrapping selector.