Apply suggestion from @hunleyd

Co-authored-by: Douglas J Hunley <doug.hunley@gmail.com>

Author: staaldraad

ansible/tasks/stage2-setup-postgres.yml

@@ -147,23 +147,24 @@
         path: '/var/lib/postgresql/.nix-profile/bin/'
       register: 'nix_links'
 
-- name: Check psql_version and install gatekeeper if not pg15
+- name: Check if psql_version is psql_15
+  set_fact:
+    is_psql_15: "{{ psql_version == 'psql_15' }}"
+    
+- name: Install gatekeeper if not pg15
+  when:
+    - stage2_nix
+    - not is_pgsql_15
   block:
-    - name: Check if psql_version is psql_15
-      set_fact:
-        is_psql_15: "{{ psql_version == 'psql_15' }}"
-
-    - name: Install gatekeeper from nix binary cache
+   - name: Install gatekeeper from nix binary cache
       become: yes
       shell: |
         sudo -u postgres bash -c ". /nix/var/nix/profiles/default/etc/profile.d/nix-daemon.sh && nix profile install github:supabase/postgres/{{ git_commit_sha }}#gatekeeper"
-      when: stage2_nix and not is_psql_15
 
     - name: Create symbolic link for linux-pam to find pam_jit_pg.so
       shell: >
         sudo ln -s /var/lib/postgresql/.nix-profile/lib/security/pam_jit_pg.so $(find /nix/store -type d -path "/nix/store/*-linux-pam-*/lib/security" -print -quit)/pam_jit_pg.so
       become: yes
-      when: stage2_nix and not is_psql_15
 
     - name: Create symlinks for Nix files into /usr/lib/postgresql/bin
       ansible.builtin.file: