Make installer not dependant to internet connection during startup #5478

Describe the suggested improvement

Is your improvement related to a problem? Please describe.

Our servers ar not allowed internet connection. Its blocked. When we start the installer it takes serveral minutes to just start the installer.
In our test environment we allow internet connection and the installer starts quickly.

Describe the suggested solution

Either have a checkbox before startup with "Offline start" or a flag to send to the .exe in a commandline/Pwsh.

Additional Context

No response