workflows/hugo: pin hugo version to previous release

The latest (0.139.5) release does not include all release assets, which
means that peaceiris/actions-hugo fails when attempting to use `latest`.
Pin it to the previous release instead, as instructed by Hugo's release
notes.

See also:
  peaceris/actions-hugo#652
  gohugoio/hugo#13147

Signed-off-by: Luca Zeuch <[email protected]>

Author: l-zeuch

.github/workflows/hugo.yml

@@ -30,7 +30,9 @@ jobs:
       - name: Install Hugo
         uses: peaceiris/actions-hugo@v3
         with:
-          hugo-version: latest
+          # FIXME: At the moment, the 0.139.5 release does not include all assets,
+          # which fails this specific step. We use the previous version instead.
+          hugo-version: '0.139.4'
           # We use the extended version just to be on the safe side.
           # It is recommended anyway.
           extended: true