message: fix: update syntax highlighting tests
diff: @@ -117,7 +117,7 @@ mod test {
  const CODEBLOCK_RENDERED: &str =
  "<pre style=\"background-color:#2b303b;\">\n\
  - <span style=\"color:#b48ead;\">mod </span>\
  + <code><span style=\"color:#b48ead;\">mod </span>\
  <span style=\"color:#c0c5ce;\">test {\n\
  </span><span style=\"color:#c0c5ce;\"> </span>\
  <span style=\"color:#b48ead;\">fn \
  @@ -128,7 +128,7 @@ mod test {
  </span><span style=\"color:#d08770;\">true\n\
  </span><span style=\"color:#c0c5ce;\"> }\n\
  </span><span style=\"color:#c0c5ce;\"> }\n\
  - </span><span style=\"color:#c0c5ce;\"> </span></pre>\n";
  + </span><span style=\"color:#c0c5ce;\"> </span></code></pre>\n";
  #[test]
  fn highlight_block_renders_rust() {
  @@ -140,9 +140,9 @@ mod test {
  const CUSTOM_CODEBLOCK: &str = "[[[]]]]";
  const CUSTOM_CODEBLOCK_RENDERED: &str = "<pre style=\"background-color:#2b303b;\">\n\
  - <span style=\"color:#c0c5ce;\">[[[]]]</span>\
  + <code><span style=\"color:#c0c5ce;\">[[[]]]</span>\
  <span style=\"background-color:#bf616a;color:#2b303b;\">]</span>\
  - </pre>\n";
  + </code></pre>\n";
  #[test]
  fn highlight_custom_syntax() {
  