chore(ci): apply fixes to the ngx_wasm_module update workflow

[flrgh]

changes

• update regex used to match NGX_WASM_MODULE in .requirements file
• improve error-handling
• cleanup workflow stdout/stderr a little bit
• convert the "scan this commit log for important things" reminder to a checklist
• add the cherry-pick kong-ee label to created PRs
• change commit author to team-gateway-bot
• mark the PR as draft
• assign the PR to me (@flrgh)

why create the PR as draft and assign to @flrgh?

There is a big flaw in all of this in that PRs created using GITHUB_TOKEN do not trigger the integration test suite. For the life of me, I cannot figure out a fully-automated workaround:

We don't want maintainers to merge the dependency update without running the tests, so for now, the PR is created as a draft as a safeguard against somebody seeing that the PR is green and merging it anyways. The PR body will include a checklist item reminding maintainers to ensure the test suite has been triggered:

[locao]

I added the "hold merge" label to remind us to test the personal token instead of GITHUB_TOKEN to run the tests before merging this change.