Cleanup quotes usage in YAML files

Seems quotes in YAML is a mess.

Official guidelines (see explanation here [1]) are following.

1. If you can get away without quotes, do not use them.
2. Use single quotes if you need quotes.
3. Use double quotes if you can't use single quotes for some reason.

Common reason for double quotes in this repository is line breaks for
long lines and control characters (\n, \t) in replacement patterns.

Hope, I didn't break anything.

Tested with following commands, because there are no changes in others.

$ ansible-playbook dotfiles.yml
$ ansible-playbook master.yml

[1]: https://stackoverflow.com/a/69850618/1313516

1 files changed, 0 insertions, 1 deletions

diff --git a/TODO.txt b/TODO.txt
index 419ecec..357b84a 100644
--- a/TODO.txt
+++ b/TODO.txt
@@ -1,6 +1,5 @@
 TODO
 
-* Fix quotes: use either single quotes or double quotes.
 * Enable linters: ansible-lint, yamllint.
 * Enable IPv6 for wireguard.
 * Setup L2TP/IPsec VPN server.