FIX: quote glob in linkcheck.yml so the workflow file parses (#333)

`args: **/*.html` is invalid YAML (a plain scalar cannot start with
`*`, the alias indicator), so GitHub has been logging a 0-second
"workflow file issue" failure for this file on every push to every
branch since #249. Quoting the glob restores a parseable workflow;
the lychee invocation itself is unchanged.

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: jstac

.github/workflows/linkcheck.yml

@@ -22,7 +22,7 @@ jobs:
         with:
           fail: false
           # Configuration is now specified in lychee.toml file
-          args: **/*.html
+          args: "**/*.html"
       - name: Create Issue From File
         if: steps.lychee.outputs.exit_code != 0
         uses: peter-evans/create-issue-from-file@v5