fix(rust): address new assert-is-empty nightly lint

The resulting code is arguably uglier, but there is a strong argument
for the improved message when the assert trips.

crates/cli/src/tests/query_test.rs

@@ -4623,7 +4623,7 @@ fn test_query_with_no_patterns() {
     allocations::record(|| {
         let language = get_language("javascript");
         let query = Query::new(&language, "").unwrap();
-        assert!(query.capture_names().is_empty());
+        assert_eq!(query.capture_names(), [] as [&str; 0]);
         assert_eq!(query.pattern_count(), 0);
     });
 }

crates/generate/src/nfa.rs

@@ -458,7 +458,7 @@ impl Nfa {
 
     #[must_use]
     pub fn last_state_id(&self) -> u32 {
-        assert!(!self.states.is_empty());
+        assert_ne!(self.states, [] as [NfaState; 0]);
         self.states.len() as u32 - 1
     }
 }