Reduce reliance on github action specific environment vars

[jdalton]

No description provided.

[graphite-app]

The debug statement logs when GITHUB_REPOSITORY is missing but the function continues execution with a potentially undefined value. Since the next line uses ownerSlashRepo without checking if it's defined, consider adding a return null after the debug call to fail early and prevent attempting to parse an undefined string.

Suggested change

	if (!GITHUB_REPOSITORY) {
	debugFn('miss: GITHUB_REPOSITORY env var')
	}
	if (!GITHUB_REPOSITORY) {
	debugFn('miss: GITHUB_REPOSITORY env var')
	return null
	}

Spotted by Diamond

Is this helpful? React 👍 or 👎 to let us know.