Fix typos reported by codespell

src/wallet/db.cpp

@@ -72,7 +72,7 @@ BerkeleyEnvironment* GetWalletEnv(const fs::path& wallet_path, std::string& data
         database_filename = "wallet.dat";
     }
     LOCK(cs_db);
-    // Note: An ununsed temporary BerkeleyEnvironment object may be created inside the
+    // Note: An unused temporary BerkeleyEnvironment object may be created inside the
     // emplace function if the key already exists. This is a little inefficient,
     // but not a big concern since the map will be changed in the future to hold
     // pointers instead of objects, anyway.