sagemathgh-38046: Fix wrong urls in changes.html

    
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Once again, we fix `changes.html`, currently broken in every PR. For
example, follow
sagemath#38041 (comment)

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URL: sagemath#38046
Reported by: Kwankyu Lee
Reviewer(s):

.ci/create-changes-html.sh

@@ -82,7 +82,7 @@ for block in diff_blocks:
         if content:
             with open(file_path, 'w') as file:
                 file.writelines(content)
-        path = 'html/' + doc
+        path = doc
         hunks = '&nbsp;'.join(f'<a href="{path}#hunk{i+1}" class="hunk" target="_blank">#{i + 1}</a>' for i in range(count))
         out_blocks.append(f'<p class="diff"><a href="{path}">{doc}</a>&nbsp;' + hunks + '&emsp;</p>'
                             + '\n<pre><code class="language-diff">'