Prior to this change, ci triggered cd, depending on the event that
triggered ci. Due to the vague information about that event
available to cd, the workflow pipeline was a bit brittle.
This change disassociates ci and cd workflows to allow for an
independent configuration of trigger events.
The test jobs, which used to be defined in ci, are now in a
separate workflow file _test.yml that can be included in both ci
and cd workflows.
**Changes in ci**
- Only defines trigger events and permissions, the "meat" of ci is
defined in the called _test.yml now.
- No longer triggers on tag pushes, this was only needed for cd.
**Changes in cd**
- Now triggers directly on tag pushes instead of (cd)-workflow_run.
- Calls _test.yml, and require successful run before build/release.
(`needs: test` replaces `if: ...`)
- Changes variable names about pushed tag that triggered the event.
Signed-off-by: Lukas Puehringer <lukas.puehringer@nyu.edu>
