Render element HtmlTag no longer adds newline

Rendering of single html tags no more adds a white space after element. Use to add '#suffix' => "\n" to keep existing behavior

Before

$element = [
  '#tag' => 'br',
];

Rendered as "<br />\n"

After

$element = [
  '#tag' => 'br',
];

Rendered as "<br />"

$element = [
  '#tag' => 'br',
  '#suffix' => "\n",
];

Rendered as "<br />\n"

Automated tests that rely on on newline should be updated to be compatible with Drupal 11.