build: docs task should not clean (#9197)

* No longer cleans the dist/ folder because some deploy scripts depend on previous output inside of the dist folder.

Author: devversion

tools/gulp/tasks/docs.ts

@@ -74,7 +74,6 @@ const markdownOptions = {
 
 /** Generate all docs content. */
 task('docs', sequenceTask(
-  'clean',
   [
     'markdown-docs-material',
     'markdown-docs-cdk',