[flake8-pie] Reuse parsed tokens (PIE800) (#15438)

## Summary

Follow-up to #15394. See [this review
comment](https://github.com/astral-sh/ruff/pull/15394#discussion_r1910526741).

## Test Plan

`cargo nextest run` and `cargo insta test`.

crates/ruff_linter/src/rules/flake8_pie/rules/unnecessary_spread.rs

@@ -1,11 +1,10 @@
 use ruff_diagnostics::{Diagnostic, Edit, Fix, FixAvailability, Violation};
 use ruff_macros::{derive_message_formats, ViolationMetadata};
 use ruff_python_ast::{self as ast, Expr};
-use ruff_python_trivia::{SimpleTokenKind, SimpleTokenizer};
+use ruff_python_parser::{TokenKind, Tokens};
 use ruff_text_size::{Ranged, TextSize};
 
 use crate::checkers::ast::Checker;
-use crate::Locator;
 
 /// ## What it does
 /// Checks for unnecessary dictionary unpacking operators (`**`).
@@ -54,7 +53,7 @@ pub(crate) fn unnecessary_spread(checker: &mut Checker, dict: &ast::ExprDict) {
             // inside a dict.
             if let Expr::Dict(inner) = value {
                 let mut diagnostic = Diagnostic::new(UnnecessarySpread, value.range());
-                if let Some(fix) = unnecessary_spread_fix(inner, prev_end, checker.locator()) {
+                if let Some(fix) = unnecessary_spread_fix(inner, prev_end, checker.tokens()) {
                     diagnostic.set_fix(fix);
                 }
                 checker.diagnostics.push(diagnostic);
@@ -68,24 +67,27 @@ pub(crate) fn unnecessary_spread(checker: &mut Checker, dict: &ast::ExprDict) {
 fn unnecessary_spread_fix(
     dict: &ast::ExprDict,
     prev_end: TextSize,
-    locator: &Locator,
+    tokens: &Tokens,
 ) -> Option<Fix> {
     // Find the `**` token preceding the spread.
-    let doublestar = SimpleTokenizer::starts_at(prev_end, locator.contents())
-        .find(|tok| matches!(tok.kind(), SimpleTokenKind::DoubleStar))?;
+    let doublestar = tokens
+        .after(prev_end)
+        .iter()
+        .find(|tok| matches!(tok.kind(), TokenKind::DoubleStar))?;
 
     if let Some(last) = dict.iter_values().last() {
         // Ex) `**{a: 1, b: 2}`
         let mut edits = vec![];
         let mut open_parens: u32 = 0;
 
-        for tok in SimpleTokenizer::starts_at(doublestar.end(), locator.contents()).skip_trivia() {
+        for tok in tokens.after(doublestar.end()) {
             match tok.kind() {
-                SimpleTokenKind::LParen => {
+                kind if kind.is_trivia() => {}
+                TokenKind::Lpar => {
                     edits.push(Edit::range_deletion(tok.range()));
                     open_parens += 1;
                 }
-                SimpleTokenKind::LBrace => {
+                TokenKind::Lbrace => {
                     edits.push(Edit::range_deletion(tok.range()));
                     break;
                 }
@@ -97,22 +99,23 @@ fn unnecessary_spread_fix(
         }
 
         let mut found_r_curly = false;
-        for tok in SimpleTokenizer::starts_at(last.end(), locator.contents()).skip_trivia() {
+        for tok in tokens.after(last.end()) {
             if found_r_curly && open_parens == 0 {
                 break;
             }
 
             match tok.kind() {
-                SimpleTokenKind::Comma => {
+                kind if kind.is_trivia() => {}
+                TokenKind::Comma => {
                     edits.push(Edit::range_deletion(tok.range()));
                 }
-                SimpleTokenKind::RParen => {
+                TokenKind::Rpar => {
                     if found_r_curly {
                         edits.push(Edit::range_deletion(tok.range()));
                         open_parens -= 1;
                     }
                 }
-                SimpleTokenKind::RBrace => {
+                TokenKind::Rbrace => {
                     edits.push(Edit::range_deletion(tok.range()));
                     found_r_curly = true;
                 }