[TIDY] Set some "diff: false", fix linter warnings

tasks/borgbackup-Debian-stretch.yml

@@ -7,31 +7,32 @@
 
 # For Debian Stretch, use a newer package version from backports
 
-- name: borgbackup - Add debian repo key
+- name: Borgbackup - Add debian repo key
   when:
     - ansible_distribution_release == 'stretch'
-  become: yes
+  become: true
   ansible.builtin.apt_key:
     keyserver: pgpkeys.mit.edu
     id: 8B48AD6246925553
     state: present
-- name: borgbackup - Add stretch-backports
+- name: Borgbackup - Add stretch-backports
   when:
     - ansible_distribution_release == 'stretch'
-  become: yes
+  become: true
   ansible.builtin.apt_repository:
     repo: deb http://ftp.debian.org/debian stretch-backports main
     state: present
-- name: borgbackup - Install borgbackup from stretch-backports
+- name: Borgbackup - Install borgbackup from stretch-backports
   when:
     - borgbackup_passphrase is defined
     - borgbackup_repo is defined
     - borgbackup_hostname is defined
     - ansible_distribution_release == 'stretch'
-  become: yes
+  become: true
   ansible.builtin.apt:
     name: borgbackup
     state: latest
     default_release: stretch-backports
-    update_cache: yes
+    update_cache: true
     cache_valid_time: 3600
+  diff: false