refact(packaging): remove unused function

Signed-off-by: innocentzero <isfarulhaque@proton.me>

crates/pacdef_core/src/grouping/package.rs

@@ -48,12 +48,6 @@ impl Package {
         }
     }
 
-    /// Returns the repo name as a reference.
-    /// Panics if repo name is `None` with a custom error message.
-    pub(crate) fn repo(&self, msg: &str) -> &str {
-        self.repo.as_ref().expect(msg)
-    }
-
     /// Try to parse a string (from a line in a group file) and return a package.
     /// From the string, any possible comment is removed and whitespace is trimmed.
     /// Returns `None` if there is nothing left after trimming.