Convert ioBroker.pushover to TypeScript without build

[Apollon77]

• Migrated main.js to src/main.ts with TypeScript syntax
• Used JavaScript private fields (#) instead of TypeScript private keyword
• Created local interface extending ioBroker.AdapterConfig for type safety
• Updated tsconfig.json to extend @tsconfig/node20 with transpileOnly for ts-node
• Updated package.json:
  • Changed main entry to src/main.ts
  • Updated @iobroker/testing to ^5.2.2 for TypeScript support
  • Added @tsconfig/node20, ts-node, and source-map-support dependencies
  • Removed chai, chai-as-promised, sinon, sinon-chai (provided by @iobroker/testing)
  • Updated files array to include src/**/*.ts instead of main.js
  • Changed test:js to test:ts for TypeScript test files
  • Updated check script to use tsconfig.json
• Updated test/mocharc.custom.json to include ts-node/register and source-map-support/register
• Added lib/**/* to ESLint ignores
• Removed deprecated files: main.js, tsconfig.check.json
• Created type declarations for pushover-notifications module
• All validations pass: npm run check, npm run lint, npm test

[GermanBluefox]

Will it be really without compiling started?