Support customize default port when build

[typed-sigterm]

Describe the feature

It helps when not going to setting environment variables.

nitro/src/presets/node/runtime/node-server.ts

Lines 25 to 26 in f3a5773

	const port = (destr(process.env.NITRO_PORT || process.env.PORT) ||
	3000) as number;

Additional information

• Would you be willing to help implement this feature?