fix: update stardoc module to `0.7.1`

[vpanta]

Found when creating a new Bazel module repository via bazel-contrib/rules-template, updating the libs to their latest version, and testing in CI with Bazel 8.0.0rc1.

That generates an error such as:

ERROR: Traceback (most recent call last):
        File "${BAZEL_DIR}/external/stardoc+/stardoc/BUILD", line 72, column 16, in <toplevel>
                srcs = glob(["*.jar"]),
Error in glob: glob pattern '*.jar' didn't match anything, but allow_empty is set to False (the default value of allow_empty can be set with --incompatible_disallow_empty_glob).
ERROR: ${REPO}/docs/BUILD.bazel:5:23: Target '@@stardoc+//stardoc:templates/markdown_tables/module_extension.vm' contains an error and its package is in error and referenced by '//docs:rules'

This was fixed by the 0.7.1 release of bazelbuild/stardoc.

[alexeagle]

This repo is green with the version of stardoc we're using, and whatever repo you created with rules-template is free to choose a newer version if it's red there. So I don't think we need this change (plus it's technically a breaking change as stardoc produces different output, hence this PR being red)