Remove redundant parentheses around awaited coroutines/tasks (#2991)

This is a tricky one as await is technically an expression and therefore
in certain situations requires brackets for operator precedence.
However, the vast majority of await usage is just await some_coroutine(...)
and similar in format to return statements. Therefore this PR removes
redundant parens around these await expressions.

Co-authored-by: Jelle Zijlstra <jelle.zijlstra@gmail.com>
Co-authored-by: Richard Si <63936253+ichard26@users.noreply.github.com>