Staging workflow is problematic

[giggio]

Describe the issue you are experiencing

If you test on Let's encrypt staging, after you remove the server the addon will not issue a new certificate, even if you try to remove the certificates fom /ssl.

What type of installation are you running?

Home Assistant OS

Which operating system are you running on?

Home Assistant Operating System

Which add-on are you reporting an issue with?

Let's Encrypt

What is the version of the add-on?

5.0.18

Steps to reproduce the issue

1. Install the addon
2. Test the configuration using acme_server: https://acme-staging-v02.api.letsencrypt.org/
3. Check certs were issued on /ssl.
4. Remove the acme_server config and certs from /ssl.
5. Start the addon again, it will recreate the staging certificates.

System Health information

N/A.

Anything in the Supervisor logs that might be useful for us?

N/A.

Anything in the add-on logs that might be useful for us?

cont-init: info: running /etc/cont-init.d/file-structure.sh
cont-init: info: /etc/cont-init.d/file-structure.sh exited 0
s6-rc: info: service legacy-cont-init successfully started
s6-rc: info: service legacy-services: starting
services-up: info: copying legacy longrun lets-encrypt (no readiness notification)
s6-rc: info: service legacy-services successfully started
[21:04:37] INFO: Selected DNS Provider: dns-cloudflare
[21:04:37] INFO: Use propagation seconds: 60
[21:04:37] INFO: Use CloudFlare token
[21:04:37] INFO: Detecting existing certificate type for xxx
Saving debug log to /var/log/letsencrypt/letsencrypt.log
[21:04:38] INFO: Existing certificate using 'ecdsa' key type.
Saving debug log to /var/log/letsencrypt/letsencrypt.log
Certificate not yet due for renewal

Additional information

Originally reported at #1705, but incorrectly closed as stale.