fix: register tar toolchain for bzlmod users (#574)

MODULE.bazel

@@ -14,12 +14,13 @@ bazel_dep(name = "platforms", version = "0.0.7")
 bazel_dep(name = "stardoc", version = "0.5.4", repo_name = "io_bazel_stardoc")
 
 ext = use_extension("@aspect_bazel_lib//lib:extensions.bzl", "ext")
-use_repo(ext, "copy_directory_toolchains", "copy_to_directory_toolchains", "coreutils_toolchains", "expand_template_toolchains", "jq_toolchains", "yq_toolchains")
+use_repo(ext, "copy_directory_toolchains", "copy_to_directory_toolchains", "coreutils_toolchains", "expand_template_toolchains", "jq_toolchains", "tar_toolchains", "yq_toolchains")
 
 register_toolchains(
     "@copy_directory_toolchains//:all",
     "@copy_to_directory_toolchains//:all",
     "@jq_toolchains//:all",
+    "@tar_toolchains//:all",
     "@yq_toolchains//:all",
     "@coreutils_toolchains//:all",
     "@expand_template_toolchains//:all",

e2e/smoke/BUILD.bazel

@@ -3,6 +3,7 @@ load("@aspect_bazel_lib//lib:copy_to_directory.bzl", "copy_to_directory")
 load("@aspect_bazel_lib//lib:diff_test.bzl", "diff_test")
 load("@aspect_bazel_lib//lib:expand_make_vars.bzl", "expand_template")
 load("@aspect_bazel_lib//lib:jq.bzl", "jq")
+load("@aspect_bazel_lib//lib:tar.bzl", "tar")
 load("@aspect_bazel_lib//lib:yq.bzl", "yq")
 
 # Validate that JQ works and resolves its toolchain
@@ -83,3 +84,10 @@ diff_test(
         "//conditions:default": "a_stamp_expected",
     }),
 )
+
+# Validate that tar works and resolves its toolchain
+tar(
+    name = "tar_empty",
+    srcs = [],
+    mtree = [],
+)