Avoid hyphenating "pagination-failure" across a line break

Copilot PR #273 review: the docstring of `_error_log_messages` wrapped
mid-compound-word as `pagination-\n    failure`, which renders as
"pagination- failure" in help output. Rephrased so the term stays on
one line.

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

Author: thodson-usgs

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 pagination-
-    failure tests below all assert against the same shape."""
+    """Pull ERROR-and-above message strings out of caplog. Shared by the
+    pagination-failure tests below."""
     return [r.getMessage() for r in caplog.records if r.levelno >= logging.ERROR]