tidy-up: miscellaneous

- badwords: replace stray synonyms with 'null-terminator'.
- tests/FILEFORMAT.md: tidy up feature descriptions.
- printf: replace stray `%i` masks with `%d` for consistency.
- pytest: add comments for empty excepts to try silencing GitHub CodeQL
  warnings.
- tool1394, unit1675: merge nested `if`s.
- dnscache: fix typo in comment.
- fix whitespace, indent and newlines.

Closes #21921

lib/doh.c

@@ -419,7 +419,7 @@ static CURLcode doh_probe_run(struct Curl_easy *data,
 
   (void)curl_easy_setopt(doh, CURLOPT_SSL_OPTIONS,
                          ((long)data->set.ssl.primary.ssl_options &
-                           ~CURLSSLOPT_AUTO_CLIENT_CERT));
+                          ~CURLSSLOPT_AUTO_CLIENT_CERT));
 
   doh->state.internal = TRUE;
   doh->master_mid = data->mid; /* master transfer of this one */