Replace mlocate with plocate on build.archlinux.org

mlocate has been replaced with plocate in the repo[1].

[1] https://lists.archlinux.org/archives/list/arch-dev-public@lists.archlinux.org/thread/6Q2OBF3VPAWII66UIA43OEZFSRGUWS4E/

playbooks/build.archlinux.org.yml

@@ -3,7 +3,7 @@
   remote_user: root
   roles:
     - { role: common }
-    - { role: tools, extra_utils: ['setconf', 'mlocate'] }
+    - { role: tools, extra_utils: ['setconf', 'plocate'] }
     - { role: firewalld }
     - { role: sshd }
     - { role: root_ssh }