Support cargo_bazel_bootstrap for bzlmod

MODULE.bazel

@@ -25,3 +25,6 @@ use_repo(
 rust = use_extension("//rust:extensions.bzl", "rust")
 rust.host_tools(edition = "2021")
 use_repo(rust, "rust_host_tools")
+
+cargo_bazel_bootstrap = use_extension("//crate_universe/private/module_extensions:cargo_bazel_bootstrap.bzl", "cargo_bazel_bootstrap")
+use_repo(cargo_bazel_bootstrap, "cargo_bazel_bootstrap")

crate_universe/deps_bootstrap.bzl

@@ -6,12 +6,13 @@ load("//crate_universe/private:srcs.bzl", "CARGO_BAZEL_SRCS")
 # buildifier: disable=bzl-visibility
 load("//rust/private:common.bzl", "rust_common")
 
-def cargo_bazel_bootstrap(name = "cargo_bazel_bootstrap", rust_version = rust_common.default_version):
+def cargo_bazel_bootstrap(name = "cargo_bazel_bootstrap", rust_version = rust_common.default_version, **kwargs):
     """An optional repository which bootstraps `cargo-bazel` for use with `crates_repository`
 
     Args:
         name (str, optional): The name of the `cargo_bootstrap_repository`.
         rust_version (str, optional): The rust version to use. Defaults to the default of `cargo_bootstrap_repository`.
+        **kwargs: kwargs to pass through to cargo_bootstrap_repository.
     """
     cargo_bootstrap_repository(
         name = name,
@@ -22,4 +23,5 @@ def cargo_bazel_bootstrap(name = "cargo_bazel_bootstrap", rust_version = rust_co
         version = rust_version,
         # The increased timeout helps avoid flakes in CI
         timeout = 900,
+        **kwargs
     )

crate_universe/private/module_extensions/cargo_bazel_bootstrap.bzl

@@ -0,0 +1,14 @@
+"""Module extension for bootstrapping cargo-bazel."""
+
+load("//crate_universe:deps_bootstrap.bzl", _cargo_bazel_bootstrap_repo_rule = "cargo_bazel_bootstrap")
+
+def _cargo_bazel_bootstrap_impl(_):
+    _cargo_bazel_bootstrap_repo_rule(
+        rust_toolchain_cargo_template = "@rust_host_tools//:bin/{tool}",
+        rust_toolchain_rustc_template = "@rust_host_tools//:bin/{tool}",
+    )
+
+cargo_bazel_bootstrap = module_extension(
+    implementation = _cargo_bazel_bootstrap_impl,
+    doc = """Module extension to generate the cargo_bazel binary.""",
+)