fix: add missing trailing newline in deploy.yaml

POSIX requires text files to end with a newline. Without it, some
tools may not process the last line correctly.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: abrgr

.github/workflows/deploy.yaml

@@ -42,4 +42,4 @@ jobs:
 
       - name: Deploy to GitHub Pages
         id: deployment
-        uses: actions/deploy-pages@v4
+        uses: actions/deploy-pages@v4