Change 'always_run: yes' to 'check_mode: no'

Removes some deprecation warnings in ansible output

roles/common/tasks/add_github_ssh_hostkey.yml

@@ -3,7 +3,7 @@
   local_action: command ssh-keyscan -t rsa github.com
   register: github_ssh_keyscan_result
   changed_when: false
-  always_run: yes
+  check_mode: no
   run_once: yes
   become: no
 

roles/common/tasks/update_everything.yml

@@ -8,7 +8,7 @@
   failed_when: false
   changed_when: false
   # Necessary to support --check mode
-  always_run: true
+  check_mode: no
 
 - name: Install sudo.
   apt: