Fix markdown math brackets render problem (#31420) (#31430)

Backport #31420 by charles7668

Co-authored-by: charles <30816317+charles7668@users.noreply.github.com>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

modules/markup/markdown/markdown_test.go

@@ -542,6 +542,10 @@ func TestMathBlock(t *testing.T) {
 			"$$a$$",
 			`<pre class="code-block is-loading"><code class="chroma language-math display">a</code></pre>` + nl,
 		},
+		{
+			"$a$ ($b$) [$c$] {$d$}",
+			`<p><code class="language-math is-loading">a</code> (<code class="language-math is-loading">b</code>) [$c$] {$d$}</p>` + nl,
+		},
 	}
 
 	for _, test := range testcases {