chore: address CodeQL code-quality findings (no behavior change) (#900)

- py/empty-except: add a short comment to each of the 10 flagged
  `except <Type>: pass` blocks explaining why swallowing the
  exception is correct there (best-effort cleanup/close, or
  intentional fall-through to the next report format).
- py/unnecessary-lambda: replace `map(lambda x: parse_email_address(x), ...)`
  with `map(parse_email_address, ...)` at the 5 flagged sites in
  parsedmarc/utils.py; parse_email_address takes exactly one
  positional argument, so this is behavior-preserving. Ran
  `ruff format` afterward, which collapsed 3 of the now-shorter
  calls onto single lines.
- py/imprecise-assert: replace `assertTrue(a > b)` / `assertTrue(a >= b)`
  with `assertGreater(a, b)` / `assertGreaterEqual(a, b)` at the 9
  flagged test sites; none carried a custom assertion message.
- .vscode/settings.json: drop three cSpell whitelist entries that are
  pure misspellings ("passsword", "httpasswd", "unparasable") and
  appear nowhere else in the tracked tree, so a recurrence of the typo
  they used to hide (see #888) would be caught again. The correctly
  spelled "htpasswd" and "unparseable" entries are untouched.

Verified clean: ruff check, ruff format --check, pyright (0
errors/warnings), and pytest tests/ (989 tests collected and passing
before and after, GITHUB_ACTIONS=true).

Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>

tests/test_utils.py

@@ -1143,7 +1143,7 @@ class TestUtilsReverseDnsMap(unittest.TestCase):
         """load_reverse_dns_map in offline mode loads bundled map"""
         rdns_map = {}
         parsedmarc.utils.load_reverse_dns_map(rdns_map, offline=True)
-        self.assertTrue(len(rdns_map) > 0)
+        self.assertGreater(len(rdns_map), 0)
 
     def testLoadReverseDnsMapLocalOverride(self):
         """load_reverse_dns_map uses local_file_path when provided"""
@@ -1169,7 +1169,7 @@ class TestUtilsReverseDnsMap(unittest.TestCase):
             side_effect=httpx.ConnectError("no network"),
         ):
             parsedmarc.utils.load_reverse_dns_map(rdns_map)
-        self.assertTrue(len(rdns_map) > 0)
+        self.assertGreater(len(rdns_map), 0)
 
     def testLoadReverseDnsMapInvalidCsvFallback(self):
         """A fetch that returns a non-map CSV body logs a warning and