In efbbae5a4, the `publish_packages_as_artifacts` CircleCI job was
created to publish the build artifacts of PR builds on CI. In a8f4f14bd,
its scope was expanded to also publish build artifacts on non-PR builds.
The published artifacts names are constructed based on the PR number
(e.g. include `-pr12345-`), so on non-PR builds the names do not reflect
the source branch (instead, they include `-prfalse-`).
This commit fixes this by using the current branch name. For example,
artifact names for the `master` or `9.0.x` branch will include
`-master-` and `-9.0.x-` respectively (instead of `-prfalse-`).
(NOTE: For PRs, where branch name is `pull/12345`, the branch name is
transformed to `pr12345`.)
PR Close#33957