Revert cached_property on WQP_Metadata.site_info

WQP_Metadata is not strictly a snapshot — a long-lived `md` reference
(paginated workflow, long-running script) would see stale site
metadata if `site_info` cached its result. Plain `@property` matches
user expectation that an attribute named `site_info` reflects the
current state, and the cost of one extra HTTP call on re-read is
acceptable. Drop the now-unused `from functools import cached_property`.

The coercion comment is retained.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: thodson-usgs

dataretrieval/wqp.py

@@ -12,7 +12,6 @@
 from __future__ import annotations
 
 import warnings
-from functools import cached_property
 from io import StringIO
 from typing import TYPE_CHECKING
 
@@ -688,7 +687,7 @@ def __init__(
         self._legacy = legacy
         self._ssl_check = ssl_check
 
-    @cached_property
+    @property
     def site_info(self):
         # Walk WQP-native key first, then legacy NWIS-style aliases. Whichever
         # matched, pass the value as `siteid` -- that's what_sites' native arg.