Improve TypeScript config

[JstnMcBrd]

Added

• exactOptionalPropertyTypes to tsconfig
• isolatedModules to tsconfig
• Missing return types on functions
• skipLibCheck to tsconfig as a workaround for discord.js type-checking issue
  • Conflict between discord.js + @nodes/types after upgrading discordjs/discord.js#10358

Changed

• All dependencies to latest versions
• vscode-eslint flat config support to be stable
• Truthy checks for certain variables to be more general and concise
• process.exit to be directly imported like other dependencies
• Command error message to use getSlashName() function
• Optional parameter adding to abide by exactOptionalPropertyTypes
• All references to Reflect.set to use Object.assign instead
• Invite button disable to be false by default
• Last updated date

Removed

• noFallthroughCasesInSwitch from tsconfig (handled better by eslint)

[JstnMcBrd]

TypeScript 5.5 throws errors when type-checking discord.js.

• Conflict between discord.js + @nodes/types after upgrading discordjs/discord.js#10358

This appears to be an undocumented breaking change with the recent update - TypeScript 5.4 works fine. Turning on skipLibCheck is a valid workaround until discord.js fixes their types.