chore: fix some comments

regex-automata/src/dfa/dense.rs

@@ -2498,7 +2498,7 @@ impl OwnedDFA {
         self.tt.set(from, byte, to);
     }
 
-    /// An an empty state (a state where all transitions lead to a dead state)
+    /// An empty state (a state where all transitions lead to a dead state)
     /// and return its identifier. The identifier returned is guaranteed to
     /// not point to any other existing state.
     ///

regex-automata/src/util/determinize/state.rs

@@ -57,7 +57,7 @@ can only be used for adding NFA state IDs and recording some assertions.
 
 The expected flow here is to use the above builders to construct a candidate
 DFA state to check if it already exists. If it does, then there's no need to
-freeze it into a `State`. It it doesn't exist, then `StateBuilderNFA::to_state`
+freeze it into a `State`. If it doesn't exist, then `StateBuilderNFA::to_state`
 can be called to freeze the builder into an immutable `State`. In either
 case, `clear` should be called on the builder to turn it back into a
 `StateBuilderEmpty` that reuses the underlying memory.