CI: use artifacts to store API dumps for later comparison (2/2)

Detailed Description

Part 2 of !2479 (merged)

Blocked by #798 (closed)

API Changes

Please tick one of the following options:

• These changes do not modify the API.
• These changes do modify the API, and are backwards compatible.
• These changes do modify the API, and are backwards incompatible.

For examples of changes that do not modify the API and/or are considered backwards (in)compatible, please see the contributing guide.

Justification for Backwards Incompatible Changes

n/a

Review Status

n/a