test: two test names quoted as the lints ask

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>

halkyon_learn_curator/test/update_test.dart

@@ -322,7 +322,7 @@ void main() {
   });
 
   test("a replaced source stays until what replaces it is there: Korean's "
-      'words from Wiktionary until KRDict\'s are', () {
+      "words from Wiktionary until KRDict's are", () {
     File('${into.path}/wiktionary-ko-en.jsonl.gz').writeAsStringSync('');
 
     expect(removeUnwanted(into, {'ko'}), isEmpty);