Bump CI workflow (#764)

Author: t-sommer

.github/workflows/gh-pages.yml

@@ -6,4 +6,4 @@ on:
 
 jobs:
   build-website:
-    uses: modelica/ma-hugo-theme/.github/workflows/build-website.yml@d91795872c3e038b24d5b2a109ae7e00b96330cb
+    uses: modelica/ma-hugo-theme/.github/workflows/build-website.yml@25ac134f820ada1ec0883de1e38c48e9019a49ec