Update alias version in mike deploy command to 0.15 in GitHub Actions workflow

Author: MariusStorhaug

.github/workflows/pages.yml

@@ -37,5 +37,5 @@ jobs:
       - run: pip install mkdocs mkdocs-material mike
 
       - run: |
-          mike deploy --push --update-aliases 0.2 latest
+          mike deploy --push --update-aliases 0.15 latest
           mike set-default --push latest