v2.1.8

Consider this version is for react19 users

The changes made by @talatkuyuk:

• Update minimum node engine as minimum v20.9.0
• Update react and react-dom 19.2.4 for development but keep peerDependency as 19.1 and above
• Update dependencies and devDependencies
• Remove next.js from devDependencies
• Add renderToStringFromStream utility function to test <MDXRemote /> as JSX component
• Update ts expect error comments for nesting components in tests
• Update ErrorBoundary components in tests
• Update exports conditions in package.json
• Add inlineSources in tsconfig.json and remove src directory from files in package.json for better source map
• Make refinements in phrasings, Update demo app links, Update security section, Add sponsorship section, Update plugin list in README.md