ci: use nix develop for static-check to get mdbook tools

Author: ammar-agent

.github/workflows/ci.yml

@@ -65,7 +65,7 @@ jobs:
         run: echo "$HOME/.local/bin" >> $GITHUB_PATH
 
       - name: Run static checks
-        run: make -j3 static-check
+        run: nix develop --command make -j3 static-check
 
   test:
     name: Unit Tests