Replace .map_or(false, $closure) with .is_some_and(closure) (#6244)

**Summary**
[Option::is_some_and](https://doc.rust-lang.org/stable/std/option/enum.Option.html#method.is_some_and)
and
[Result::is_ok_and](https://doc.rust-lang.org/std/result/enum.Result.html#method.is_ok_and)
are new methods is rust 1.70. I find them way more readable than
`.map_or(false, ...)`.

The changes are `s/.map_or(false,/.is_some_and(/g`, then manually
switching to `is_ok_and` where the value is a Result rather than an
Option.

**Test Plan** n/a^

crates/ruff_python_stdlib/src/identifiers.rs

@@ -5,10 +5,7 @@ use crate::keyword::is_keyword;
 pub fn is_identifier(name: &str) -> bool {
     // Is the first character a letter or underscore?
     let mut chars = name.chars();
-    if !chars
-        .next()
-        .map_or(false, |c| c.is_alphabetic() || c == '_')
-    {
+    if !chars.next().is_some_and(|c| c.is_alphabetic() || c == '_') {
         return false;
     }
 
@@ -41,7 +38,7 @@ pub fn is_module_name(name: &str) -> bool {
     let mut chars = name.chars();
     if !chars
         .next()
-        .map_or(false, |c| c.is_ascii_lowercase() || c == '_')
+        .is_some_and(|c| c.is_ascii_lowercase() || c == '_')
     {
         return false;
     }