roles: strict truthy values

According to Ansible we can use yes, true, True, "or any quoted st-
ring" for a boolean true, but ansible-lint wants us to use either
true or false.

See: https://chronicler.tech/red-hat-ansible-yes-no-and/

roles/php-fpm/tasks/Debian_10.yml

@@ -11,7 +11,7 @@
         - php-curl
 
   - name: Install php-fpm and deps
-    ansible.builtin.apt: name={{ php_fpm_packages }} state=present update_cache=yes
+    ansible.builtin.apt: name={{ php_fpm_packages }} state=present update_cache=true
 
   # only copy php-fpm config for vhosts that need WordPress or PHP
   - name: Copy php-fpm pool config

roles/php-fpm/tasks/Ubuntu_18.04.yml

@@ -11,7 +11,7 @@
         - php-curl
 
   - name: Install php-fpm and deps
-    ansible.builtin.apt: name={{ php_fpm_packages }} state=present update_cache=yes
+    ansible.builtin.apt: name={{ php_fpm_packages }} state=present update_cache=true
 
   # only copy php-fpm config for vhosts that need WordPress or PHP
   - name: Copy php-fpm pool config

roles/php-fpm/tasks/Ubuntu_20.04.yml

@@ -12,7 +12,7 @@
         - php7.4-xml
 
   - name: Install php-fpm and deps
-    ansible.builtin.apt: name={{ php_fpm_packages }} state=present update_cache=yes
+    ansible.builtin.apt: name={{ php_fpm_packages }} state=present update_cache=true
 
   # only copy php-fpm config for vhosts that need WordPress or PHP
   - name: Copy php-fpm pool config

roles/php-fpm/tasks/main.yml

@@ -6,25 +6,25 @@
 
 # If any of the vhosts on this host need WordPress then we need to install PHP.
 # This uses selectattr to filter the list of dicts in nginx_vhosts, selecting
-# any that have has_wordpress defined, and has_wordpress set to True.
+# any that have has_wordpress defined, and has_wordpress set to true.
 #
 # See: https://stackoverflow.com/a/31896249
 - name: Check if any vhost needs WordPress
   ansible.builtin.set_fact:
-    install_php: True
-  when: "nginx_vhosts | selectattr('has_wordpress', 'defined') | selectattr('has_wordpress', 'equalto', True) | list | length > 0"
+    install_php: true
+  when: "nginx_vhosts | selectattr('has_wordpress', 'defined') | selectattr('has_wordpress', 'equalto', true) | list | length > 0"
 
 # Legacy, was only for Piwik, but leaving for now.
 - name: Check if any vhost needs PHP
   ansible.builtin.set_fact:
-    install_php: True
-  when: "nginx_vhosts | selectattr('needs_php', 'defined') | selectattr('needs_php', 'equalto', True) | list | length > 0"
+    install_php: true
+  when: "nginx_vhosts | selectattr('needs_php', 'defined') | selectattr('needs_php', 'equalto', true) | list | length > 0"
 
 # If install_php has not been set, then we assume no vhosts need PHP. This is
 # a bit hacky, but it's the closest we come to an if/then/else.
-- name: Set install_php to False
+- name: Set install_php to false
   ansible.builtin.set_fact:
-    install_php: False
+    install_php: false
   when: install_php is not defined
 
 - name: Configure php-fpm on Ubuntu 18.04