pkg: add react 19 as supported peer dependency

[rithvikvibhu]

Fixes #46

Currently, adding react-cmdk to a project with react 19 requires --legacy-peer-deps since react-cmdk's package.json only lists react until 18.x.

https://github.com/albingroen/react-cmdk/blob/f41e75dff26126a15001987ae75131de10959283/package.json#L61-L64

# New project
❯ npm init -y
Wrote to /tmp/test-r19-cmdk/package.json:

{
  "name": "test-r19-cmdk",
  "version": "1.0.0",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "description": ""
}

# Add react 19
❯ npm i react

added 1 package, and audited 2 packages in 1s

found 0 vulnerabilities

# Add react-cmdk
❯ npm i react-cmdk
npm error code ERESOLVE
npm error ERESOLVE unable to resolve dependency tree
npm error
npm error While resolving: [email protected]
npm error Found: [email protected]
npm error node_modules/react
npm error   react@"^19.1.0" from the root project
npm error
npm error Could not resolve dependency:
npm error peer react@"^16.x || ^17.x || ^18.x" from [email protected]
npm error node_modules/react-cmdk
npm error   react-cmdk@"*" from the root project
npm error
npm error Fix the upstream dependency conflict, or retry
npm error this command with --force or --legacy-peer-deps
npm error to accept an incorrect (and potentially broken) dependency resolution.
npm error
npm error
npm error For a full report see:
npm error /home/rithvik/.npm/_logs/2025-07-06T17_22_13_252Z-eresolve-report.txt

npm error A complete log of this run can be found in: /home/rithvik/.npm/_logs/2025-07-06T17_22_13_252Z-debug-0.log

[lucasrivoiro]

I need this too. Thz!

[syntaqx]

Would be lovely to get this merged in so I can remove my override :)