Apply Copilot PR #273 review: logger.error + future-proof helper docstring

Two small follow-ups from Copilot's review of 9c6481f:

- Revert `logger.exception` -> `logger.error` in both `_walk_pages` and
  `get_stats_data` except blocks. The PR description always advertised
  `logger.error("Request incomplete: %s", e)`; the simplify pass had
  switched to `logger.exception(...)` (which auto-attaches a traceback)
  but mid-pagination failures are expected, best-effort cases — the
  exception text is already in the message via `%s`, and a per-page
  traceback would be noisy. Reverting matches the PR description and
  the original intent.

- Drop the literal count from `_error_log_messages`'s docstring. The
  prior wording ("the four pagination-failure tests below") was already
  stale-prone, and Copilot flagged it. Replaced with a count-free
  phrasing so future test additions don't render it misleading.

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

Author: thodson-usgs

dataretrieval/waterdata/utils.py

@@ -683,7 +683,7 @@ def _walk_pages(
                 dfs.append(_get_resp_data(resp, geopd=geopd))
                 curr_url = _next_req_url(resp)
             except Exception as e:  # noqa: BLE001
-                logger.exception("Request incomplete: %s", e)
+                logger.error("Request incomplete: %s", e)
                 logger.warning(
                     "Request failed for URL: %s. Data download interrupted.", curr_url
                 )
@@ -1147,7 +1147,7 @@ def get_stats_data(
                 all_dfs.append(_handle_stats_nesting(body, geopd=GEOPANDAS))
                 next_token = body["next"]
             except Exception as e:  # noqa: BLE001
-                logger.exception("Request incomplete: %s", e)
+                logger.error("Request incomplete: %s", e)
                 logger.warning(
                     "Request failed for URL: %s (next_token=%s). "
                     "Data download interrupted.",

tests/waterdata_utils_test.py

@@ -107,8 +107,8 @@ def _resp_ok(features):
 
 
 def _error_log_messages(caplog):
-    """Pull ERROR-and-above message strings out of caplog. The four
-    pagination-failure tests below all assert against the same shape."""
+    """Pull ERROR-and-above message strings out of caplog. The pagination-
+    failure tests below all assert against the same shape."""
     return [r.getMessage() for r in caplog.records if r.levelno >= logging.ERROR]