fix: selectively pass env for container titles

closes #3007

src/node/markdown/plugins/containers.ts

@@ -43,7 +43,9 @@ function createContainer(
         const info = token.info.trim().slice(klass.length).trim()
         const attrs = md.renderer.renderAttrs(token)
         if (token.nesting === 1) {
-          const title = md.renderInline(info || defaultTitle, { ...env })
+          const title = md.renderInline(info || defaultTitle, {
+            references: env.references
+          })
           if (klass === 'details')
             return `<details class="${klass} custom-block"${attrs}><summary>${title}</summary>\n`
           return `<div class="${klass} custom-block"${attrs}><p class="custom-block-title">${title}</p>\n`