Issue #3422537 by bbrala, cmlara, dww, longwave, joachim: Autoresolve cspell...

Issue #3422537 by bbrala, cmlara, dww, longwave, joachim: Autoresolve cspell GIT_DEPTH issue when diff fails

(cherry picked from commit 7821e759)

.gitlab-ci.yml

-# cspell:ignore codequality Micheh micheh webide updatedb stylelintrc
+# cspell:ignore codequality Micheh micheh webide updatedb stylelintrc unshallow
 
 ################
 # Drupal GitLabCI template.
@@ -466,6 +466,7 @@ default:
       else
         echo "HEAD is $(git rev-parse HEAD). \$CI_MERGE_REQUEST_DIFF_BASE_SHA is ${CI_MERGE_REQUEST_DIFF_BASE_SHA}";
       fi;
+    - git diff ${CI_MERGE_REQUEST_TARGET_BRANCH_SHA:-$CI_MERGE_REQUEST_DIFF_BASE_SHA} --name-only 2>1 > /dev/null || (echo "Warning, cannot find changed files, converting to full clone." & (git fetch --unshallow --quiet && echo "Fetch successful."))
     - git diff ${CI_MERGE_REQUEST_TARGET_BRANCH_SHA:-$CI_MERGE_REQUEST_DIFF_BASE_SHA} --name-only | sed "s_^_../_" | yarn --cwd=./core run -s spellcheck:core --no-must-find-files --file-list stdin
 
 '📔 Validatable config':