chore: clear compiler warnings introduced by the Python host work

Drop two unneeded mut bindings in tests and mark the generated dict/enum
converters allow(dead_code), since a kind can leave one unused.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

plugins/opencad-python/build/generate.rs

@@ -587,6 +587,7 @@ fn gen_unit_enum(name: &str, info: &TypeInfo) -> String {
 {name_arms}    }}
 }}
 
+#[allow(dead_code)]
 fn str_to_{snake}(value: String, vm: &VirtualMachine) -> PyResult<{path}> {{
     match value.as_str() {{
 {parse_arms}        other => Err(vm.new_value_error(format!("ocs: unsupported {name} value: {{other}}"))),
@@ -656,6 +657,7 @@ fn gen_tagged_enum(name: &str, info: &TypeInfo, registry: &TypeRegistry) -> Stri
 {to_arms}    }}
 }}
 
+#[allow(dead_code)]
 fn dict_to_{snake}(value: PyObjectRef, vm: &VirtualMachine) -> PyResult<{path}> {{
     let dict = value.try_into_value::<rustpython_vm::builtins::PyDictRef>(vm)?;
     let kind = dict.get_item("kind", vm)?.try_into_value::<String>(vm)?;
@@ -732,6 +734,7 @@ fn gen_struct(name: &str, info: &TypeInfo, registry: &TypeRegistry, required: &[
 {to_dict_body}    Ok(dict.into())
 }}
 
+#[allow(dead_code)]
 fn dict_to_{snake}(value: PyObjectRef, vm: &VirtualMachine) -> PyResult<{path}> {{
     let dict = value.try_into_value::<rustpython_vm::builtins::PyDictRef>(vm)?;
     let allowed: &[&str] = &[{allowed_list}];

src/app/plugin_host.rs

@@ -7100,7 +7100,7 @@ mod tests {
         let mut app = OpenCADStudio::new_for_test();
         app.tabs[0].is_start = false;
         let mut host = HostSession::new(&mut app, 0);
-        let mut object = |host: &mut HostSession<'_>, data: ClassObjectData| {
+        let object = |host: &mut HostSession<'_>, data: ClassObjectData| {
             let handle = host.document_mut().allocate_handle();
             let mut class_object = ClassObject::new(data);
             class_object.handle = handle;
@@ -7340,7 +7340,7 @@ mod tests {
             std::path::Path::new(&plugin_path), &mut host, crate::plugin::v4_support::notification_handler(),
         ).unwrap();
         let dir = std::env::temp_dir();
-        let mut run = |host: &mut HostSession<'_>, tag: &str, body: &str| {
+        let run = |host: &mut HostSession<'_>, tag: &str, body: &str| {
             let script = dir.join(format!("ocs_layers_{tag}_{}.py", std::process::id()));
             std::fs::write(&script, format!(concat!(
                 "def P(x, y, z): return {{'x': x, 'y': y, 'z': z}}\n",