BREAKING CHANGE: Updating the Go version to 1.23

* fix: lower TTL for positive DNS-01 responses

* fix(client): DNS-01 TXT record check

properly implements `Wait` and does not proceed with ACME if TXT record
is not present and does not include the expected value.

this will lower the number of failed registrations and retries + allows
us to remove 5s sleep

adds optional delay before initial registration (when no cert exists yet)

* fix: set SOA minimum TTL to 1 day

minimize the need for returning "NODATA-A/AAAA" responses
See: #52

* fix(acme): empty TXT to control TTL of DNS-01

this ensures we ALWAYS control TTL of ACME DNS-01 response
and keep it very low (10s here) to ensure "not set" response is not
cached for hours due to minimal TTL from SOA

* fix: defensive check against bugs in datastore

if dynamodb starts returning empty strings, we want to see that
reflected in metrics

* test: DNS01NotSetValue

making sure we always return "empty" txt