fix(docker): add build arg for NEXT_PUBLIC_VAPID_PUBLIC_KEY

Dockerfile

@@ -11,6 +11,11 @@ RUN npm install
 COPY . .
 # Use a temporary DB for generation
 ENV DATABASE_URL="file:./temp.db"
+
+# Build arguments for public env vars
+ARG NEXT_PUBLIC_VAPID_PUBLIC_KEY
+ENV NEXT_PUBLIC_VAPID_PUBLIC_KEY=$NEXT_PUBLIC_VAPID_PUBLIC_KEY
+
 RUN npx prisma generate
 RUN npm run build