test: improve test to also check for "at"

Author: mcanouil

tests/docs/smoke-all/2025/07/13/11750.qmd

@@ -9,7 +9,16 @@ _quarto:
     html:
       ensureFileRegexMatches:
         - 
+          - '<p><a href="#fig-test" class="quarto-xref">Figure&nbsp;1</a></p>'
           - '<p><a href="https://github.com/mcanouil">@mcanouil</a></p>'
 ---
 
+::: {#fig-test}
+Not a figure
+
+But a caption
+:::
+
+@fig-test
+
 @mcanouil