Rollup merge of #77127 - camelid:update-mdbook, r=Dylan-DPC

Update mdBook

0.4.2 -> 0.4.3

Also updated version requirement in `Cargo.toml` from 0.4.0 to 0.4.3.

Cargo.lock

@@ -1848,9 +1848,9 @@ dependencies = [
 
 [[package]]
 name = "mdbook"
-version = "0.4.2"
+version = "0.4.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b75e31ae4eaa0e45e17ee2b6b9e3ed969c3c6ff12bb4c2e352c42493f4ebb706"
+checksum = "29be448fcafb00c5a8966c4020c2a5ffbbc333e5b96d0bb5ef54b5bd0524d9ff"
 dependencies = [
  "ammonia",
  "anyhow",

src/tools/rustbook/Cargo.toml

@@ -9,6 +9,6 @@ edition = "2018"
 clap = "2.25.0"
 
 [dependencies.mdbook]
-version = "0.4.0"
+version = "0.4.3"
 default-features = false
 features = ["search"]