Modified the list_models function to dynamically construct the model URL
by using an environment variable for the HuggingFace domain. This allows
for greater flexibility in specifying the domain and ensures that the
modification is also compatible with the Hub client library. By
supporting different environments or requirements without hardcoding the
domain name, this change facilitates the use of custom HuggingFace
domains not only within our code but also when interacting with the Hub
client library.