fix(rsc): only use web/src/entries.ts as the rscBuildAnalyze entry point

[jtoar]

Right now rscBuildAnalyze scans three entry points and ~1600 files for 'use client' and 'use server' directives.

{
  entries: "~/redwood-app/web/src/entries.ts",
  "entry.server": "~/redwood-app/web/src/entry.server.tsx",
  Document: "~/redwood-app/web/src/Document.tsx",
}

Checked with @Tobbe and the only entry point we actually need to scan is web/src/entries.ts. With this change, we only scan 267 files.

[jtoar]

The Vite docs say we can just make this a string inline here instead of needing another config block so seeing if that'll go. See https://vitejs.dev/config/build-options#build-ssr.