Uses new metadata added in https://github.com/zanieb/packse/pull/61 to
assert that resolution succeeded or failed _and_ that the installed
package versions match the expected result.
Previously, we just pulled the latest commit from `main` on every
update. This causes problems when you do not intend to update the
scenarios as in #787.
This bumps to the latest `packse` commit without new scenarios.
Following #757, improves the script for generating scenario test cases
with:
- A requirements file
- Support for downloading packse scenarios from GitHub dynamically
- Running rustfmt on the generated test file
- Updating snapshots / running tests
Zanie Blue