searx: Remove

Got succeeded by searxng.
Add searxng role

Only basic configuration for now.
Successor for searx.

Closes: https://todo.xenrox.net/~xenrox/infrastructure/16
CI: Switch to ntfy access token authentication
alertmanager: Switch to ntfy access token authentication

For ntfy-alertmanager.
ntfy_client: Switch to access token authentication
CI: Add python-passlib package

Used for hashing passwords with bcrypt.
ntfy_server: Update config

2.0.0 release.
Fix ansible-lint failures with "mode"

Forbidden implicit octal value ...
srht: Update robots.txt
grafana: Update config

 9.3.6 release.
ssh: Update sshd config
alertmanager: Set external URL

This is used for better integration with ntfy-alertmanager.
alertmanager: Update ntfy-alertmanager config
alertmanager: Proxy ntfy-alertmanager with nginx

Exposing it is necessary for the "Silence" feature.
grafana: Add basic auth to Alertmanager datasource
alertmanager: Proxy with nginx

Needed for ntfy-alertmanager.
prometheus: Config file should not be world readable

There are multiple secrets contained inside.
alertmanager: Protect with basic auth

Alertmanager will get exposed with nginx, so silence integration with
ntfy-alertmanager can work.
Make ansible-lint happy
borg: Update sqlite backup

The mumble-server has a new database location now.