impr(PR labels): automatically label PRs "waiting for review/update" (@sanidhyas3s)

[sanidhyas3s]

Description

Add a workflow/action to edit labels "waiting for review" and "waiting for updates".

Checks

• Check if any open issues are related to this PR; if so, be sure to tag them below.
• Make sure the PR title follows the Conventional Commits standard. (https://www.conventionalcommits.org for more info)
• Make sure to include your GitHub username prefixed with @ inside parentheses at the end of the PR title.

[sanidhyas3s]

Not able to make the triggers work (atleast in my fork). Documentation is barely available and my only reference is discussion threads for GH Actions and they claim that the trigger works, but when I tested it, adding reviewers didn't trigger the workflow. Done

[Miodec]

test