[Docs Site] Use |= instead of ^= in footnotes fnref selector (#19264)

Author: KianNH

src/scripts/footnotes.ts

@@ -10,7 +10,7 @@ if (footnotes) {
 			const content = note.querySelector("p") as HTMLParagraphElement;
 
 			const fnrefs = document.querySelectorAll<HTMLAnchorElement>(
-				`a[id^='${note.id.replace("fn", "fnref")}']`,
+				`a[id|='${note.id.replace("fn", "fnref")}']`,
 			);
 
 			for (const fnref of fnrefs) {