feat: complete migration to Deno with automated releases

- Remove old Node.js infrastructure (package.json, tsconfig.json, bin/nupst launcher, setup.sh)
- Update install.sh to download pre-compiled binaries from Gitea releases
- Add Gitea Actions CI/CD workflows:
  - ci.yml: Type checking, linting, and build verification
  - release.yml: Automated binary compilation and release on tags
- Update .gitignore for Deno-focused project structure
- Binary-based distribution requires no dependencies or build steps

npmextra.json

@@ -1 +0,0 @@
-{}