docs: typo file extension (#72272)

## Summary
Change [language and
filename](https://nextjs.org/docs/canary/community/contribution-guide#language-and-filename)
for match code block language.

### Improving Documentation

- [x] Run `pnpm prettier-fix` to fix formatting issues before opening
the PR.
- [x] Read the Docs Contribution Guide to ensure your contribution
follows the docs guidelines:
https://nextjs.org/docs/community/contribution-guide

Co-authored-by: JJ Kasper <[email protected]>

Author: JamBalaya56562

errors/invalid-getserversideprops-value.mdx

@@ -10,7 +10,7 @@ In one of the page's `getServerSideProps` the return value had the incorrect sha
 
 Make sure to return the following shape from `getServerSideProps`:
 
-```ts filename="pages/example.js"
+```tsx filename="pages/example.tsx"
 export async function getServerSideProps(ctx: GetServerSidePropsContext) {
   return {
     props: { [key: string]: any }

errors/no-document-viewport-meta.mdx

@@ -11,7 +11,7 @@ The viewport tag should be handled by `next/head` in `pages/_app.js`.
 
 Set your viewport `meta` tag in `pages/_app.js` instead:
 
-```tsx filename="pages/_app.js"
+```jsx filename="pages/_app.js"
 import Head from 'next/head'
 
 function MyApp({ Component, pageProps }) {