[subresource-integrity] fix: initialize strongest with null w3c/webappsec-subresource-integrity@679d685

（和訳には織り込み済み）

Author: triple-underscore

webappsec-subresource-integrity-ja.html

@@ -116,7 +116,7 @@
 
 ●●options
 
-spec_date:2025-06-12
+spec_date:2025-06-30
 trans_update:2025-06-14
 source_checked:210222
 page_state_key:WEBAPPSEC
@@ -1374,9 +1374,9 @@ <h4 title="Get the strongest metadata from set.">3.3.3. 集合から最も強い
 Let result be the empty set＼
 </li>
 	<li>
-%最強~index ~LET −1
+%最強~index ~LET −1【！~NULL】
 ◎
-and strongest be the empty string.
+and strongest be null.
 ◎
 ↓</li>
 	<li>