Remove winapi feature flag checks

These checks were impossible to trigger as there is no separate feature
flag for winapi and crossterm_winapi. The windows feature flag
automatically enables these dependencies.

src/lib.rs

@@ -252,9 +252,3 @@ pub(crate) mod macros;
 
 #[cfg(all(windows, not(feature = "windows")))]
 compile_error!("Compiling on Windows with \"windows\" feature disabled. Feature \"windows\" should only be disabled when project will never be compiled on Windows.");
-
-#[cfg(all(winapi, not(feature = "winapi")))]
-compile_error!("Compiling on Windows with \"winapi\" feature disabled. Feature \"winapi\" should only be disabled when project will never be compiled on Windows.");
-
-#[cfg(all(crossterm_winapi, not(feature = "crossterm_winapi")))]
-compile_error!("Compiling on Windows with \"crossterm_winapi\" feature disabled. Feature \"crossterm_winapi\" should only be disabled when project will never be compiled on Windows.");