public_facing: skip no-tabs linter rule on single task

Instead of skipping ansible-lint's no-tabs rule globally, apply it on
this single task that uses a tab (\t) character.

Longer-term, we could replace this tab with a space because /etc/hosts
can use either whitespace character. I'm taking a cautious approach
today for simplicity.

.ansible-lint

@@ -18,7 +18,6 @@ skip_list:
   - no-handler
   - no-jinja-when
   - no-relative-paths
-  - no-tabs
   - package-latest
   - risky-file-permissions
   - risky-shell-pipe

roles/public_facing/tasks/letsencrypt_nginx.yml

@@ -16,7 +16,7 @@
     state: present
 
 # 'letsencrypt renew' fails because it can't reach the letsencrypt authority server using IPv6
-- name: Create cron entry to force IPv4 connectivity to letsencrypt authority server
+- name: Create cron entry to force IPv4 connectivity to letsencrypt authority server  # noqa no-tabs
   cron:
     name: "Forces letsencrypt to use IPv4 when accessing acme-v01.api.letsencrypt.org"
     hour: "0"