refactor: remove dead mk_static macro from esp module

rust/src/hal/esp.rs

@@ -120,15 +120,6 @@ pub struct Esp<'a> {
 // CPU cores/threads, reconsider this.
 unsafe impl Send for Esp<'_> {}
 
-macro_rules! mk_static {
-    ($t:ty,$val:expr) => {{
-        static STATIC_CELL: static_cell::StaticCell<$t> = static_cell::StaticCell::new();
-        #[deny(unused_attributes)]
-        let x = STATIC_CELL.uninit().write(($val));
-        x
-    }};
-}
-
 impl Esp<'_> {
     pub fn get_time(&self) -> DateTime<Utc> {
         DateTime::from_timestamp_micros(self.rtc.current_time_us() as i64)