fix: add shebang to index.ts for node execution

[situ2001]

When using pnpm, everything works well. But when it comes to npm, error occured:

➜  examples npm i @oxc-node/cli 

added 26 packages, and audited 27 packages in 505ms

2 packages are looking for funding
  run `npm fund` for details

found 0 vulnerabilities
➜  examples npm exec oxnode    
import-im6.q16: unable to open X server `' @ error/import.c/ImportImageCommand/346.
import-im6.q16: unable to open X server `' @ error/import.c/ImportImageCommand/346.
import-im6.q16: unable to open X server `' @ error/import.c/ImportImageCommand/346.
import-im6.q16: unable to open X server `' @ error/import.c/ImportImageCommand/346.
/home/situ/Codes/examples/node_modules/.bin/oxnode: 6: //#region: not found
/home/situ/Codes/examples/node_modules/.bin/oxnode: 7: var: not found
/home/situ/Codes/examples/node_modules/.bin/oxnode: 8: Syntax error: word unexpected (expecting ")")

After adding shebang, the CLI works with npm exec oxnode

[situ2001]

Here is the worked CLI output.

➜  examples sed -i '1i\#!/usr/bin/env node' ./node_modules/@oxc-node/cli/dist/index.js
➜  examples ls node_modules/.bin -al                                                  
total 8
drwxrwxr-x 2 situ situ 4096  8月 31 14:34 .
drwxrwxr-x 8 situ situ 4096  8月 31 14:34 ..
lrwxrwxrwx 1 situ situ   30  8月 31 14:34 oxnode -> ../@oxc-node/cli/dist/index.js
➜  examples npm exec oxnode                                                           
Welcome to Node.js v22.14.0.
Type ".help" for more information.
>