fix(theme-common): isSamePath should be case-insensitive (#6758)

packages/docusaurus-theme-common/src/utils/pathUtils.ts

@@ -5,12 +5,15 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-// Compare the 2 paths, ignoring trailing /
+// Compare the 2 paths, case insensitive and ignoring trailing slash
 export const isSamePath = (
   path1: string | undefined,
   path2: string | undefined,
 ): boolean => {
   const normalize = (pathname: string | undefined) =>
-    !pathname || pathname?.endsWith('/') ? pathname : `${pathname}/`;
+    (!pathname || pathname?.endsWith('/')
+      ? pathname
+      : `${pathname}/`
+    )?.toLowerCase();
   return normalize(path1) === normalize(path2);
 };