Remove unnecessary #[allow] annots

Reduce the number of lint exceptions that are not necessary with the
current state of the code (or more recent toolchain)

crates/nu-command/src/dataframe/eager/columns.rs

@@ -55,7 +55,6 @@ impl Command for ColumnsDF {
     }
 }
 
-#[allow(clippy::needless_collect)]
 fn command(
     _engine_state: &EngineState,
     _stack: &mut Stack,

crates/nu-command/src/dataframe/eager/dtypes.rs

@@ -56,7 +56,6 @@ impl Command for DataTypes {
     }
 }
 
-#[allow(clippy::needless_collect)]
 fn command(
     _engine_state: &EngineState,
     _stack: &mut Stack,

crates/nu-command/src/filesystem/cp.rs

@@ -25,7 +25,6 @@ const GLOB_PARAMS: nu_glob::MatchOptions = nu_glob::MatchOptions {
 #[derive(Clone)]
 pub struct Cp;
 
-#[allow(unused_must_use)]
 impl Command for Cp {
     fn name(&self) -> &str {
         "cp"

crates/nu-command/src/filesystem/mv.rs

@@ -20,7 +20,6 @@ const GLOB_PARAMS: nu_glob::MatchOptions = nu_glob::MatchOptions {
 #[derive(Clone)]
 pub struct Mv;
 
-#[allow(unused_must_use)]
 impl Command for Mv {
     fn name(&self) -> &str {
         "mv"

crates/nu-command/src/filters/group_by.rs

@@ -38,7 +38,6 @@ impl Command for GroupBy {
         group_by(engine_state, stack, call, input)
     }
 
-    #[allow(clippy::unwrap_used)]
     fn examples(&self) -> Vec<Example> {
         vec![
             Example {

crates/nu-command/src/filters/split_by.rs

@@ -35,7 +35,6 @@ impl Command for SplitBy {
         split_by(engine_state, stack, call, input)
     }
 
-    #[allow(clippy::unwrap_used)]
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "split items by column named \"lang\"",

crates/nu-command/src/formats/to/md.rs

@@ -270,15 +270,10 @@ fn get_output_string(
 
         output_string.push_str("\n|");
 
-        #[allow(clippy::needless_range_loop)]
-        for i in 0..headers.len() {
+        for &col_width in column_widths.iter().take(headers.len()) {
             if pretty {
                 output_string.push(' ');
-                output_string.push_str(&get_padded_string(
-                    String::from("-"),
-                    column_widths[i],
-                    '-',
-                ));
+                output_string.push_str(&get_padded_string(String::from("-"), col_width, '-'));
                 output_string.push(' ');
             } else {
                 output_string.push('-');

crates/nu-command/src/math/reducers.rs

@@ -1,7 +1,6 @@
 use nu_protocol::{ShellError, Span, Value};
 use std::cmp::Ordering;
 
-#[allow(dead_code)]
 pub enum Reduce {
     Summation,
     Product,

crates/nu-command/src/viewers/table.rs

@@ -774,7 +774,6 @@ fn convert_to_table(
 }
 
 #[allow(clippy::too_many_arguments)]
-#[allow(clippy::into_iter_on_ref)]
 fn convert_to_table2<'a>(
     row_offset: usize,
     input: impl Iterator<Item = &'a Value> + ExactSizeIterator + Clone,