Is there any way I can use expo eas build fully offline without requiring an Internet connection.
Maybe an offline package or ...
You can just run eas build with --local param like
eas build --platform android --local or eas build --platform ios --local (note, plataform all is not allowed in this case).
Its in the documentation: https://docs.expo.dev/build-reference/local-builds/ (altought I found this question first)