Move st to Void-only source tools, remove bookokrat

- bookokrat removed completely from desktop_source_tools
- st moved from common to desktop_void_source_tools (Void-only; uses X11/make)
- Build task loop extended to include desktop_void_source_tools on Void

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

ansible/inventory/group_vars/void.yml

@@ -1,4 +1,11 @@
 ---
+desktop_void_source_tools:
+  - name: st
+    repo: https://codeberg.org/fscotto/st
+    build_cmd: make
+    binary_name: st
+    install_name: st
+
 void_packages_base:
   - 7zip
   - NetworkManager