Fix incorrect language selected in language selector (#21648)

Due to filtering after enumeration, initial candidate ids are assigned
incorrectly. This later causes the wrong item to be picked up when
accessed via index in the vector.

crates/language_selector/src/language_selector.rs

@@ -104,14 +104,15 @@ impl LanguageSelectorDelegate {
         let candidates = language_registry
             .language_names()
             .into_iter()
-            .enumerate()
-            .filter_map(|(candidate_id, name)| {
+            .filter_map(|name| {
                 language_registry
                     .available_language_for_name(&name)?
                     .hidden()
                     .not()
-                    .then(|| StringMatchCandidate::new(candidate_id, name))
+                    .then_some(name)
             })
+            .enumerate()
+            .map(|(candidate_id, name)| StringMatchCandidate::new(candidate_id, name))
             .collect::<Vec<_>>();
 
         Self {