fix: update spectral core and node

[mnaumanali94]

Fixes: stoplightio/spectral#955

[Copilot]

Pull Request Overview

This PR updates the Node.js version requirements in package.json and upgrades Docker base images to Node.js 18.

• Bump package.json engine range from Node 12/14 to Node 18/20
• Update Dockerfile builder, dependencies, and runtime stages to use Node 18 images

Reviewed Changes

Copilot reviewed 2 out of 3 changed files in this pull request and generated 2 comments.

File	Description
package.json	Updated the engines.node range to `^18.18
Dockerfile	Switched all node:16 stages to node:18 and added a comment separator before the builder stage

Comments suppressed due to low confidence (1)

Dockerfile:1

• [nitpick] The added comment separator before the builder stage is inconsistent with the rest of the file; consider standardizing or removing it.

###############################################################

[Copilot]

Consider pinning the base image to a specific patch version (e.g., node:18.18) to ensure reproducible builds.

Suggested change

	FROM node:18 as builder
	FROM node:18.18 as builder

[Copilot]

[nitpick] For clarity and strict version control, consider specifying full semver ranges like ">=18.18.0 <19.0.0 || >=20.17.0".

Suggested change

	"node": "^18.18 || >= 20.17"
	"node": ">=18.18.0 <19.0.0 || >=20.17.0"