Prepare for mdbook 0.5 (rust-lang#15965)

samueltardieu · web-flow · commit c5714b0f0c81 · 2025-10-27T08:31:11.000Z
The `multilingual` field has been removed in mdbook 0.5. Additionally
this removes the unnecessary `src` value which defaults to the same
value.

changelog: none
diff --git a/book/book.toml b/book/book.toml
@@ -1,8 +1,6 @@
 [book]
 authors = ["The Rust Clippy Developers"]
 language = "en"
-multilingual = false
-src = "src"
 title = "Clippy Documentation"
 
 [rust]
