Set locale in publish docs workflow

Some runners use native name encoding of latin1, Elixir (and ex_doc) expect utf-8 encoding. This is
fixed by setting the LANG environmant variable to C.UTF-8 and ensuring the locale is generated.

Signed-off-by: Winford <winford@object.stream>

Author: UncleGrumpy

.github/workflows/publish_docs.yml

@@ -21,13 +21,21 @@ permissions:
   pages: write
   id-token: write
 
+env:
+  LANG: C.UTF-8
+
 jobs:
 
   build:
     runs-on: ubuntu-24.04
     container: erlang:28
     steps:
 
+    - name: "Set locale"
+      run: |
+          sudo locale-gen C.UTF-8
+          sudo update-locale LANG="C.UTF-8"
+
     - name: "Checkout code"
       uses: actions/checkout@v5