Remove the unnecessary flatpak feature flag

crates/pacdef_core/src/backend/actual/mod.rs

@@ -4,5 +4,4 @@ pub mod arch;
 pub mod debian;
 pub mod python;
 pub mod rust;
-#[cfg(feature = "flatpak")]
 pub mod flatpak;

crates/pacdef_core/src/backend/mod.rs

@@ -18,6 +18,5 @@ pub enum Backends {
     Debian,
     Python,
     Rust,
-    #[cfg(feature = "flatpak")]
     Flatpak,
 }