v9.1.2-canary.4

Patches

• Fix SPR always revalidating in production: #9091
• Optimize script tags: #9048
• [using-preact] Update example to Preact X: #9079
• Fix language fallback in with-react-intl example: #8894
• Update legacy _app context: #9083
• Simplify with-noscript example: #9094
• Update with-react-toolbox example to use /public: #9099
• [using-inferno] Update inferno to v7.3, fix missing React.createContext function: #9038
• [with-typescript] Updated TypeScript example to use API routes: #9073
• Fix SPR header name: #9104

Credits

Huge thanks to @ijjk, @atcastle, @rafaelalmeidatk, @s-h-a-d-o-w, @devknoll, @HaNdTriX, @ismamz, and @resir014 for helping!