[ENH] - Relax Ingress Check When Using DNS Challenge

[aktech]

Feature description

• Relax the ingress check when acme_challenge_type=dns is used.
• Optionally, provide a warning instead of a hard failure if the ingress DN is not resolvable.

This is relevant after #2957 is merged.

Value and/or benefit

Currently, Nebari enforces an ingress check that requires a valid DNS resolution (to ingress IP) before proceeding with deploying anything after the kubernetes_ingress stage

nebari/src/_nebari/stages/kubernetes_ingress/__init__.py

Line 64 in 3c22840

def check_ingress_dns(stage_outputs: Dict[str, Dict[str, Any]], disable_prompt: bool):

However, when using the DNS Challenge for Let's Encrypt, this check is not required since the certificate issuance does not rely on the ingress IP pointing to DNS record, but rather on just the DNS records.

This can be overly restrictive because when deploying Nebari in a private network, the DNS may not always point to the ingress IP address, like say there is a custom proxy in between:

    +-------------+
    |  DNS Record |
    +-------------+
           |
           v
    +---------------+
    |  Custom Proxy |
    +---------------+
           |
           v
    +-------------+
    |  Ingress IP |
    +-------------+
           |
           v
+-------------------+
|  Private Network  |
+-------------------+

Anything else?

No response