Apply nightly clippy fixes (#11083)

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# Description
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Clippy fixes for rust 1.76.0-nightly

# User-Facing Changes
<!-- List of all changes that impact the user experience here. This
helps us keep track of breaking changes. -->

N/A
# Tests + Formatting
<!--
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- `cargo fmt --all -- --check` to check standard code formatting (`cargo
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crates/nu-command/src/filters/group_by.rs

@@ -271,7 +271,7 @@ fn group_closure(
                         ));
                     }
 
-                    let value = match collection.get(0) {
+                    let value = match collection.first() {
                         Some(Value::Error { .. }) | None => Value::string(error_key, span),
                         Some(return_value) => return_value.clone(),
                     };

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

@@ -171,7 +171,7 @@ fn insert(
             ctrlc,
         )
     } else {
-        if let Some(PathMember::Int { val, .. }) = cell_path.members.get(0) {
+        if let Some(PathMember::Int { val, .. }) = cell_path.members.first() {
             let mut input = input.into_iter();
             let mut pre_elems = vec![];
 

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

@@ -221,7 +221,7 @@ fn reject(
     let mut new_rows = vec![];
     for column in cell_paths {
         let CellPath { ref members } = column;
-        match members.get(0) {
+        match members.first() {
             Some(PathMember::Int { val, span, .. }) => {
                 if members.len() > 1 {
                     return Err(ShellError::GenericError(

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

@@ -212,7 +212,7 @@ fn select(
 
     for column in columns {
         let CellPath { ref members } = column;
-        match members.get(0) {
+        match members.first() {
             Some(PathMember::Int { val, span, .. }) => {
                 if members.len() > 1 {
                     return Err(ShellError::GenericError(

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

@@ -190,7 +190,7 @@ pub fn transpose(
 
     if args.header_row {
         for i in input.iter() {
-            if let Some(desc) = descs.get(0) {
+            if let Some(desc) = descs.first() {
                 match &i.get_data_by_key(desc) {
                     Some(x) => {
                         if let Ok(s) = x.as_string() {

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

@@ -171,7 +171,7 @@ fn update(
             )?
             .set_metadata(mdclone))
     } else {
-        if let Some(PathMember::Int { val, span, .. }) = cell_path.members.get(0) {
+        if let Some(PathMember::Int { val, span, .. }) = cell_path.members.first() {
             let mut input = input.into_iter();
             let mut pre_elems = vec![];
 

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

@@ -186,7 +186,7 @@ fn upsert(
             ctrlc,
         )
     } else {
-        if let Some(PathMember::Int { val, span, .. }) = cell_path.members.get(0) {
+        if let Some(PathMember::Int { val, span, .. }) = cell_path.members.first() {
             let mut input = input.into_iter();
             let mut pre_elems = vec![];
 

crates/nu-command/src/formats/from/nuon.rs

@@ -59,7 +59,7 @@ impl Command for FromNuon {
         let mut block = nu_parser::parse(&mut working_set, None, string_input.as_bytes(), false);
 
         if let Some(pipeline) = block.pipelines.get(1) {
-            if let Some(element) = pipeline.elements.get(0) {
+            if let Some(element) = pipeline.elements.first() {
                 return Err(ShellError::GenericError(
                     "error when loading nuon text".into(),
                     "could not load nuon text".into(),

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

@@ -79,7 +79,7 @@ pub fn min(data: Vec<Value>, span: Span, head: Span) -> Result<Value, ShellError
 }
 
 pub fn sum(data: Vec<Value>, span: Span, head: Span) -> Result<Value, ShellError> {
-    let initial_value = data.get(0);
+    let initial_value = data.first();
 
     let mut acc = match initial_value {
         Some(v) => {
@@ -124,7 +124,7 @@ pub fn sum(data: Vec<Value>, span: Span, head: Span) -> Result<Value, ShellError
 }
 
 pub fn product(data: Vec<Value>, span: Span, head: Span) -> Result<Value, ShellError> {
-    let initial_value = data.get(0);
+    let initial_value = data.first();
 
     let mut acc = match initial_value {
         Some(v) => {