Fix issues reported by PHPCS

MR Raised

Hi

I reviewed MR!8, applied against Shortcode 2.0.3, and confirmed fixes the issues reported by phpcs.

➜  shortcode git:(main) ✗ curl https://git.drupalcode.org/project/shortcode/-/merge_requests/8.diff | patch -p1
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100  5248    0  5248    0     0  12752      0 --:--:-- --:--:-- --:--:-- 12958
patching file 'shortcode_basic_tags/templates/shortcode-button.html.twig'
patching file 'shortcode_basic_tags/templates/shortcode-clear.html.twig'
patching file 'shortcode_basic_tags/templates/shortcode-dropcap.html.twig'
patching file 'shortcode_basic_tags/templates/shortcode-img.html.twig'
patching file 'shortcode_basic_tags/templates/shortcode-item.html.twig'
patching file 'shortcode_basic_tags/templates/shortcode-link.html.twig'
patching file 'shortcode_basic_tags/templates/shortcode-quote.html.twig'
patching file 'src/ShortcodeService.php'
➜  shortcode git:(main) ✗ cd ..
➜  contrib git:(main) ✗ phpcs --standard=Drupal,DrupalPractice --extensions=php,module,inc,install,test,profile,theme,css,info,txt,md,yml,twig shortcode
➜  contrib git:(main) ✗

It all passed PHPCS using Gitlab CI.

Moving this to RTBC.
Thank you.