Update dependency io_bazel_stardoc to v0.5.6

Author: renovate[bot]

internal_deps.bzl

@@ -55,9 +55,9 @@ def rules_helm_internal_deps():
     maybe(
         http_archive,
         name = "io_bazel_stardoc",
-        sha256 = "c9794dcc8026a30ff67cf7cf91ebe245ca294b20b071845d12c192afe243ad72",
+        sha256 = "dfbc364aaec143df5e6c52faf1f1166775a5b4408243f445f44b661cfdc3134f",
         urls = [
-            "https://mirror.bazel.build/github.com/bazelbuild/stardoc/releases/download/0.5.0/stardoc-0.5.0.tar.gz",
-            "https://github.com/bazelbuild/stardoc/releases/download/0.5.0/stardoc-0.5.0.tar.gz",
+            "https://mirror.bazel.build/github.com/bazelbuild/stardoc/releases/download/0.5.6/stardoc-0.5.6.tar.gz",
+            "https://github.com/bazelbuild/stardoc/releases/download/0.5.6/stardoc-0.5.6.tar.gz",
         ],
     )