Regression: next/dynamic conditionally importing client components adds both to client bundle in Next.js 15 (used to work in 14)

### Link to the code that reproduces this issue https://github.com/gonmpablo/NextDynamicIssue ### To Reproduce Next.js 14: Go to this URL: https://next-dynamic-issue-git-ec7cb0-pablo-gonzalez-martinezs-projects.vercel.app/ Observe: Only the used component’s chunk is included in the client bundle. Next.js 15: Go to this URL: https://next-dynamic-issue-git-09c334-pablo-gonzalez-martinezs-projects.vercel.app/ Observe: Both chunks for ClientA and ClientB are included, despite the conditional rendering ### Current vs. Expected behavior Current (Next.js 15): When using next/dynamic() to conditionally import two client components (e.g., ClientA, ClientB), both chunks are sent to the client, even though only one is rendered at runtime. Expected (Next.js 14 behavior): Only the chunk of the component actually rendered should be sent to the client. This was working correctly in v14 and helped significantly reduce TBT. ### Provide environment information ```bash NEXT JS 15: { "dependencies": { "next": "15.3.3", "react": "^19.0.0", "react-dom": "^19.0.0" }, "devDependencies": { "@eslint/eslintrc": "^3", "@next/bundle-analyzer": "^15.3.3", "@types/node": "^20", "@types/react": "^19", "@types/react-dom": "^19", "eslint": "^9", "eslint-config-next": "15.3.3", "typescript": "^5" } } NEXT JS 14: { "dependencies": { "react": "18.2.0", "react-dom": "18.2.0", "next": "14.2.28" }, "devDependencies": { "typescript": "^5", "@types/node": "^20", "@next/bundle-analyzer": "14.2.28", "@types/react": "18.2.0", "@types/react-dom": "18.2.0", "eslint-config-next": "14.2.28", "@eslint/eslintrc": "^3" } } ``` ### Which area(s) are affected? (Select all that apply) dynamicIO, Performance ### Which stage(s) are affected? (Select all that apply) Other (Deployed), Vercel (Deployed), next start (local), next build (local), next dev (local) ### Additional context Could be something related to this change? h…