use zip for cleaner iteration with 1-based index

Author: xtqqczze

src/uu/dircolors/src/dircolors.rs

@@ -364,8 +364,7 @@ where
     let mut state = ParseState::Global;
     let mut saw_colorterm_match = false;
 
-    for (num, line) in user_input.into_iter().enumerate() {
-        let num = num + 1;
+    for (num, line) in (1..).zip(user_input.into_iter()) {
         let line = line.borrow().purify();
         if line.is_empty() {
             continue;

src/uu/sort/src/sort.rs

@@ -1799,8 +1799,7 @@ fn emit_debug_warnings(
 
     show_error!("{}", translate!("sort-warning-simple-byte-comparison"));
 
-    for (idx, selector) in settings.selectors.iter().enumerate() {
-        let key_index = idx + 1;
+    for (key_index, selector) in (1..).zip(settings.selectors.iter()) {
         if let Some(legacy) = legacy_warnings
             .iter()
             .find(|warning| warning.key_index == Some(key_index))