Add rules_license style declaration.

- Done for both WORKSPACE and bzlmod styles
- The dependency is different because rules_license is not
  up to date in the BCR. I'll correct that at the next
  rules_license release.

BUILD

diff --git a/BUILD b/BUILD
index c38493e..7aea923 100644
--- a/BUILD
+++ b/BUILD
@@ -1,6 +1,17 @@
-package(default_visibility = ["//visibility:public"])
+load("@rules_license//rules:license.bzl", "license")
 
-licenses(["notice"])
+package(
+    default_applicable_licenses = [":license"],
+    default_visibility = ["//visibility:public"],
+)
+
+license(
+    name = "license",
+    license_kinds = [
+        "@rules_license//licenses/spdx:Apache-2.0"
+    ],
+    license_text = "LICENSE",
+)
 
 exports_files(["LICENSE"])
 

MODULE.bazel

diff --git a/MODULE.bazel b/MODULE.bazel
index e4f4cfd..34badd4 100644
--- a/MODULE.bazel
+++ b/MODULE.bazel
@@ -1,5 +1,7 @@
 module(
     name = "platforms",
-    version = "0.0.6",  # keep in sync with version.bzl
+    version = "0.0.8",  # keep in sync with version.bzl
     compatibility_level = 1,
 )
+
+bazel_dep(name = "rules_license", version = "0.0.3")

WORKSPACE

diff --git a/WORKSPACE b/WORKSPACE
index f1874ea..28137ef 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -1 +1,9 @@
 workspace(name = "platforms")
+
+http_archive(
+    name = "rules_license",
+    urls = [
+        "https://mirror.bazel.build/github.com/bazelbuild/rules_license/releases/download/0.0.3/rules_license-0.0.3.tar.gz",
+    ],
+    # sha256 = "4865059254da674e3d18ab242e21c17f7e3e8c6b1f1421fffa4c5070f82e98b5",
+)

WORKSPACE.bzlmod

diff --git a/WORKSPACE.bzlmod b/WORKSPACE.bzlmod
new file mode 100644
index 0000000..59c0af4
--- /dev/null
+++ b/WORKSPACE.bzlmod
@@ -0,0 +1,4 @@
+# Include dependencies which are only needed for development here.
+#
+# Even if this is empty, you need it with bzlmod enable to prevent
+# bzlmod from bringing in WORKSPACE too.