ZoneInfoNotFoundError: 'No time zone found with key Asia/Calcutta' during Setup Wizard on Python 3.14 Pilot-ERPNext

When setting up a fresh instance of Frappe/ERPNext v16 using Pilot on an Ubuntu machine in India, the Setup Wizard crashes at step 3 (setup-wizard/3) with a ZoneInfoNotFoundError.

### App Versions
```
{
"frappe": "16.33.0",
"erpnext": "16.30.0"
}
```
### Route
```
setup-wizard/0
```
### Traceback
```
Traceback (most recent call last):
File "/home/sadhu/.local/share/uv/python/cpython-3.14.7-linux-x86_64-gnu/lib/python3.14/zoneinfo/_common.py", line 12, in load_tzdata
path = resources.files(package_name).joinpath(resource_name)
~~~~~~~~~~~~~~~^^^^^^^^^^^^^^
File "/home/sadhu/.local/share/uv/python/cpython-3.14.7-linux-x86_64-gnu/lib/python3.14/importlib/resources/_common.py", line 46, in wrapper
return func(anchor)
File "/home/sadhu/.local/share/uv/python/cpython-3.14.7-linux-x86_64-gnu/lib/python3.14/importlib/resources/_common.py", line 56, in files
return from_package(resolve(anchor))
~~~~~~~^^^^^^^^
File "/home/sadhu/.local/share/uv/python/cpython-3.14.7-linux-x86_64-gnu/lib/python3.14/functools.py", line 982, in wrapper
return dispatch(args[0].__class__)(*args, **kw)
~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^
File "/home/sadhu/.local/share/uv/python/cpython-3.14.7-linux-x86_64-gnu/lib/python3.14/importlib/resources/_common.py", line 82, in _
return importlib.import_module(cand)
~~~~~~~~~~~~~~~~~~~~~~~^^^^^^
File "/home/sadhu/.local/share/uv/python/cpython-3.14.7-linux-x86_64-gnu/lib/python3.14/importlib/__init__.py", line 88, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "", line 1406, in _gcd_import
File "", line 1371, in _find_and_load
File "", line 1314, in _find_and_load_unlocked
File "", line 491, in _call_with_frames_removed
File "", line 1406, in _gcd_import
File "", line 1371, in _find_and_load
File "", line 1314, in _find_and_load_unlocked
File "", line 491, in _call_with_frames_removed
File "", line 1406, in _gcd_import
File "", line 1371, in _find_and_load
File "", line 1335, in _find_and_load_unlocked
ModuleNotFoundError: No module named 'tzdata'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "apps/frappe/frappe/app.py", line 139, in application
init_request(request)
~~~~~~~~~~~~^^^^^^^^^
File "apps/frappe/frappe/app.py", line 242, in init_request
frappe.local.http_request = HTTPRequest()
~~~~~~~~~~~^^
File "apps/frappe/frappe/auth.py", line 42, in __init__
self.set_session()
~~~~~~~~~~~~~~~~^^
File "apps/frappe/frappe/auth.py", line 79, in set_session
frappe.local.login_manager = LoginManager()
~~~~~~~~~~~~^^
File "apps/frappe/frappe/auth.py", line 137, in __init__
self.make_session(resume=True)
~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^
File "apps/frappe/frappe/auth.py", line 228, in make_session
frappe.local.session_obj = Session(
~~~~~~~^
user=self.user,
^^^^^^^^^^^^^^^
...<4 lines>...
audit_user=audit_user,
^^^^^^^^^^^^^^^^^^^^^^
)
^
File "apps/frappe/frappe/sessions.py", line 236, in __init__
self.resume()
~~~~~~~~~~~^^
File "apps/frappe/frappe/sessions.py", line 322, in resume
data = self.get_session_record()
File "apps/frappe/frappe/sessions.py", line 338, in get_session_record
r = self.get_session_data()
File "apps/frappe/frappe/sessions.py", line 355, in get_session_data
data = self.get_session_data_from_db()
File "apps/frappe/frappe/sessions.py", line 386, in get_session_data_from_db
.where(sessions.lastupdate > get_expired_threshold())
~~~~~~~~~~~~~~~~~~~~~^^
File "apps/frappe/frappe/sessions.py", line 512, in get_expired_threshold
now = frappe.utils.now()
File "apps/frappe/frappe/utils/data.py", line 424, in now
return now_datetime().strftime(DATETIME_FORMAT)
~~~~~~~~~~~~^^
File "apps/frappe/frappe/utils/data.py", line 373, in now_datetime
return datetime.datetime.now(ZoneInfo(get_system_timezone())).replace(tzinfo=None)
~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^
File "/home/sadhu/.local/share/uv/python/cpython-3.14.7-linux-x86_64-gnu/lib/python3.14/zoneinfo/_common.py", line 29, in load_tzdata
raise ZoneInfoNotFoundError(f"No time zone found with key {key}")
zoneinfo._common.ZoneInfoNotFoundError: 'No time zone found with key Asia/Calcutta'

```
### Request Data
```
{
"type": "POST",
"args": {
"args": "{\"currency\":\"INR\",\"country\":\"India\",\"timezone\":\"Asia/Calcutta\",\"language\":\"English\",\"full_name\":\"asdf\",\"email\":\"asdf2@gmai.com\",\"password\":\",./\",\"persona_implementing_for\":\"A client I'm consulting for\",\"persona_company_size\":\"1–10\",\"persona_industry\":\"Manufacturing\",\"persona_current_system\":\"Tally\",\"module_accounting\":1,\"module_stock\":1,\"module_manufacturing\":1,\"module_projects\":0,\"company_name\":\"demo kk\",\"company_abbr\":\"DK\",\"chart_of_accounts\":\"India - Chart of Accounts\",\"fy_start_date\":\"2026-04-01\",\"fy_end_date\":\"2027-03-31\",\"setup_demo\":0}"
},
"headers": {},
"error_handlers": {},
"url": "/api/method/frappe.desk.page.setup_wizard.setup_wizard.setup_complete",
"request_id": null
}
```
### Response Data
```
{
"exception": "zoneinfo._common.ZoneInfoNotFoundError: 'No time zone found with key Asia/Calcutta'",
"exc_type": "ZoneInfoNotFoundError"
}
```

Start at the setup_wizard.setup_complete endpoint and trace the failure through apps/frappe/frappe/auth.py, sessions.py, and utils/data.py, especially get_expired_threshold() and now_datetime(). Reproduce the fresh-instance setup on Python 3.14 with timezone Asia/Calcutta. Done means the setup wizard completes without ZoneInfoNotFoundError and timezone handling remains covered by an appropriate test.

Written by the indexing model from the issue text.