chore(deps): support express 5

[dderevjanik]

This pull request addresses an issue with dependency resolution in the express-slow-down package. Currently, the package specifies a peer dependency on Express >= 4, which leads to conflicts when installed in projects using Express 5.0.0-beta.3 or higher.

Error log when installing on project with express 5

npm ERR! code ERESOLVE
npm ERR! ERESOLVE unable to resolve dependency tree
npm ERR! 
npm ERR! While resolving: myproject@1.0.0
npm ERR! Found: express@5.0.0-beta.3
npm ERR! node_modules/express
npm ERR!   express@"5.0.0-beta.3" from the root project
npm ERR! 
npm ERR! Could not resolve dependency:
npm ERR! peer express@">= 4" from express-slow-down@2.0.1
npm ERR! node_modules/express-slow-down
npm ERR!   express-slow-down@"*" from the root project
npm ERR! 
npm ERR! Fix the upstream dependency conflict, or retry
npm ERR! this command with --force or --legacy-peer-deps
npm ERR! to accept an incorrect (and potentially broken) dependency resolution.

[gamemaker1]

Thank you!