📝 Update db migration command instructions (baptisteArno#1410)

Since you proxy the prisma commands so they have the right env varaible
for DATABASE_URL & the ___location for schema.prisma file

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Co-authored-by: Baptiste Arnaud <[email protected]>

Author: Emmet-v15

apps/docs/self-hosting/deploy/manual.mdx

@@ -43,7 +43,7 @@ cp .env.example .env
 
 <Note>
   The database user should have the `SUPERUSER` role. You can setup and migrate
-  the database with the `pnpm prisma generate && pnpm db:migrate` command.
+  the database with the `pnpm db:migrate` command.
 </Note>
 
 3. Install dependencies