Do not use the PPA when >= 22.04.

defaults/main.yml

@@ -1,6 +1,6 @@
 ---
-redis_install: True
-redis_enabled: True
+redis_install: true
+redis_enabled: true
 # https://launchpad.net/~chris-lea/+archive/ubuntu/redis-server
 redis_ppa_repo: ppa:chris-lea/redis-server
 redis_pkg_state: present
@@ -12,5 +12,5 @@ redis_conf_files:
   - redis.conf
 
 redis_tcp_port: 6379
-redis_bind_localhost: True
+redis_bind_localhost: true
 redis_append_only_mode: 'no'

tasks/main.yml

@@ -2,6 +2,7 @@
 - block:
     - name: Install the Redis PPA
       apt_repository: repo='{{ redis_ppa_repo }}' update_cache=yes
+      when: ansible_distribution_version is version_compare('20.04', '<=')
 
     - name: Install the Redis packages
       apt: name={{ redis_server_pkg }} state={{ redis_pkg_state }} cache_valid_time=1800