Hi Andrii, my name is Jose, a Windows user like you. I'll be happy to assist you with this issue. I'm sorry to hear you're experiencing this issue.
You are trying to remove English keyboard layout. Unfortunately, to continue using English as display language at least one keyboard must be added. It isn't required to be an English layout. On English language package, you can add a Polish layout and set as default, then you will be able to remove the English layout. In that case, you must remove Polish language if you are only using it as keyboard layout.
Please let me know if you need any further assistance.