fix: remove broken Sass linting from Sass compilation task and move it to build task

fix: remove broken Sass linting from Sass compilation task and move it to build task

Changes:
- Remove broken Sass linting from the `sass:foundation` task. The `finish` gulp event is an stream internal event and is not suitable to chain tasks.
- Add `lint:graceful`, `lint:graceful:sass` and `lint:graceful:javascript` to check for linting errors without throwing errors and breaking the chain of tasks.
- Call `lint:graceful` on the build task. For now, there is too much linting issues to display them at each Sass/Javascript compilation.