Vendor dependencies

Let's see how I like this workflow.

vendor/cxx/WORKSPACE

@@ -0,0 +1,31 @@
+workspace(name = "cxx.rs")
+
+load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
+
+http_archive(
+    name = "rules_rust",
+    sha256 = "617082067629939c0a22f587811a3e822a50a203119a90380e21f5aec3373da9",
+    strip_prefix = "rules_rust-e07881fa22a5f0d16230d8b23bbff2bf358823b8",
+    urls = [
+        # Main branch as of 2022-04-27
+        "https://github.com/bazelbuild/rules_rust/archive/e07881fa22a5f0d16230d8b23bbff2bf358823b8.tar.gz",
+    ],
+)
+
+load("@rules_rust//rust:repositories.bzl", "rules_rust_dependencies", "rust_register_toolchains")
+
+RUST_VERSION = "1.65.0"
+
+rules_rust_dependencies()
+
+rust_register_toolchains(
+    version = RUST_VERSION,
+)
+
+load("//tools/bazel:vendor.bzl", "vendor")
+
+vendor(
+    name = "third-party",
+    cargo_version = RUST_VERSION,
+    lockfile = "//third-party:Cargo.lock",
+)