How to rewrite a task for the 4th Gulp?

Question

gulp.js

Please help me rewrite the task in gulpfile.
I remade my hapfile for the 4th version and I can't overcome a couple of bugs.
1. task 'removedist '
Fixed it by adding async and await
Is this a good solution?
2. The main problem is that the buildFiles, buildCss, buildJs, buildFonts variables in the "build" task, which transferred the code to the dist folder, are not executed.

Here is the project completely on GIT:
https://github.com/drMonro/stroyrem26.ru