firebase deploy is ignoring next build flags

### [REQUIRED] Environment info

**firebase-tools:** 15.2.1

**Platform:** Windows 11 Pro

### [REQUIRED] Steps to reproduce

run "firebase deploy"

### [REQUIRED] Expected behavior

Build with webpack instead turbopack

### [REQUIRED] Actual behavior

"firebase deploy" is ignoring package.json build script flags "next build --webpack". Please allow to use flags so we can choose to build with turbopack or webpack freely, current versions of next.js defaults to turbopack if you dont specify the webpack flag and firebase cli is ignoring flags and just running "next build"