WORKSPACE: update rules_rust and replace cargo-raze with crate_universe

cargo-raze is deprecated, unmaintained and doesn't build anymore.
create_universe reduces the clutter inside the repo and allows simpler
setup of rust requirements.

Change-Id: Iebe88902ae469a28c0378707447f7d97006d0479
Reviewed-on: https://review.monogon.dev/c/monogon/+/2749
Reviewed-by: Lorenz Brun <lorenz@monogon.tech>
Tested-by: Jenkins CI
diff --git a/metropolis/handbook/defs.bzl b/metropolis/handbook/defs.bzl
index c875980..8944e9a 100644
--- a/metropolis/handbook/defs.bzl
+++ b/metropolis/handbook/defs.bzl
@@ -105,7 +105,7 @@
             doc = "The mdbook tool.",
             executable = True,
             cfg = "host",
-            default = "@dev_source_monogon//third_party/rust:cargo_bin_mdbook",
+            default = "@crate_index//:mdbook__mdbook",
         ),
     },
 )