[6.15.z] Setting sanity hostname attr initially

[Satellite-QE]

Cherrypick of PR: #15350

Problem Statement

Sanity is failing with server.hostname attribute not found. Earlier the dynaconf validator was setting it as a default value and attribute but that Is removed in PR #15340.

Solution

Setting the hostname attribute to server for sanity.

Local Testing

In [2]: settings.server.hostname
---------------------------------------------------------------------------
BoxKeyError                               Traceback (most recent call last)
Cell In[2], line 1
----> 1 settings.server.hostname

File ~/venv/robottelo312/src/dynaconf/dynaconf/utils/boxing.py:18, in evaluate_lazy_format.<locals>.evaluate(dynabox, item, *args, **kwargs)
     16 @wraps(f)
     17 def evaluate(dynabox, item, *args, **kwargs):
---> 18     value = f(dynabox, item, *args, **kwargs)
     19     settings = dynabox._box_config["box_settings"]
     21     if getattr(value, "_dynaconf_lazy_format", None):

File ~/venv/robottelo312/src/dynaconf/dynaconf/utils/boxing.py:41, in DynaBox.__getattr__(self, item, *args, **kwargs)
     39 except (AttributeError, KeyError):
     40     n_item = find_the_correct_casing(item, self) or item
---> 41     return super().__getattr__(n_item, *args, **kwargs)

File ~/venv/robottelo312/src/dynaconf/dynaconf/vendor/box/box.py:360, in Box.__getattr__(self, item)
    358     if self._box_config['default_box']:
    359         return self.__get_default(item)
--> 360     raise BoxKeyError(str(err)) from None
    361 return value

BoxKeyError: "'DynaBox' object has no attribute 'hostname'"

In [3]: settings.set("server.hostname", None)

In [4]: type(settings.server.hostname)
NoneType

[Satellite-QE]

trigger: test-robottelo
pytest: tests/foreman -m build_sanity -k test_satellite_installation

[Satellite-QE]

PRT Result

Build Number: 7314
Build Status: UNSTABLE
PRT Comment: pytest tests/foreman -m build_sanity -k test_satellite_installation --external-logging
Test Result : ======== 1 failed, 5442 deselected, 5450 warnings in 1162.00s (0:19:21) ========

[jyejare]

The PRT failed but is not related to this PR, it's a product failure, hence merging.