DNSroboCert 3.9.0

Modified

• Update Lexicon to 3.5.5 (add Mythic Beasts and Infomaniak providers)
• Update Certbot to 1.13.0
• Update docker images to Python 3.9.2
• Use poetry-core to build DNSroboCert (#306)
• Various fixes on the documentation (#291 #292)

Removed

• Stop using --manual-public-ip-logging-ok deprecated flag on Certbot