Fix case mismatch between notify and handler name

The ansible-lint fix in 6371f59 capitalised the handler name to
'Restart postgresql' but left the two notify references as
'restart postgresql'. Ansible handler matching is case-sensitive,
so the handler never fired and PostgreSQL was never restarted after
its config was written, causing Molecule tests to fail.

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

Author: kaapstorm

roles/postgres/tasks/main.yml

@@ -65,7 +65,7 @@
     src: postgres/postgresql.conf.j2
     dest: /etc/postgresql/{{ postgresql_version }}/main/postgresql.conf
     mode: "0640"
-  notify: restart postgresql
+  notify: Restart postgresql
   tags:
     - provision
     - postgres
@@ -77,7 +77,7 @@
     src: postgres/pg_hba.conf.j2
     dest: /etc/postgresql/{{ postgresql_version }}/main/pg_hba.conf
     mode: "0640"
-  notify: restart postgresql
+  notify: Restart postgresql
   tags:
     - provision
     - postgres