trying to fix deploy preview fail

Author: Dionysios Grapsas

.github/workflows/docs_preview.yml

@@ -36,3 +36,14 @@ jobs:
           source-dir: docs/_build/html
           preview-branch: gh-pages
           custom-url: fortls.fortran-lang.org
+      - name: Setup Git
+        run: |
+          git config user.name "github-actions[bot]"
+          git config user.email "github-actions[bot]@users.noreply.github.com"
+      - name: Build and Deploy
+        run: |
+          # Commands to build and deploy documentation
+          git checkout -b gh-pages
+          git add -A
+          git commit -m "Deploy preview for PR ${GITHUB_REF##*/} 🛫"
+          git push --force origin gh-pages