chore: remove time_utils.rs

No longer needed time_utils in lightning-invoice

Author: DhananjayPurohit

lightning-invoice/src/lib.rs

@@ -30,8 +30,6 @@ compile_error!("at least one of the `std` or `no-std` features must be enabled")
 pub mod payment;
 pub mod utils;
 
-pub(crate) mod time_utils;
-
 extern crate bech32;
 extern crate bitcoin_hashes;
 #[macro_use] extern crate lightning;