[ty] Invert dependencies of ty_combine and ty_python_semantic (#22191)

crates/ty_python_semantic/src/python_platform.rs

@@ -1,4 +1,5 @@
 use std::fmt::{Display, Formatter};
+use ty_combine::Combine;
 
 /// The target platform to assume when resolving types.
 #[derive(Debug, Clone, PartialEq, Eq, get_size2::GetSize)]
@@ -54,6 +55,10 @@ impl Default for PythonPlatform {
     }
 }
 
+impl Combine for PythonPlatform {
+    fn combine_with(&mut self, _other: Self) {}
+}
+
 #[cfg(feature = "schemars")]
 mod schema {
     use crate::PythonPlatform;