doc: use is_some_and instead of map_or(false, _)

see
https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_map_or

Author: ada4a

book/src/development/common_tools_writing_lints.md

@@ -141,7 +141,7 @@ impl LateLintPass<'_> for MyStructLint {
             // we are looking for the `DefId` of `Drop` trait in lang items
             .drop_trait()
             // then we use it with our type `ty` by calling `implements_trait` from Clippy's utils
-            .map_or(false, |id| implements_trait(cx, ty, id, &[])) {
+            .is_some_and(|id| implements_trait(cx, ty, id, &[])) {
                 // `expr` implements `Drop` trait
             }
     }