This PR ensures that we enter a lock inside the `@SendableProperty`
implementation as soon as we access a computed property. Additionally,
it mirrors the access level of the original property. Both changes are
required for [improved
accuracy](https://github.com/apple/container/pull/144) of progress
updates in container. Additionally, it should resolve
https://github.com/apple/containerization/issues/60 that occurs on
certain configurations.
Please tag as 0.1.1 after merging.
This removes two image push tests. We cannot have the CI push to our
ghcr registry since external users do not have write access for pushing
the image. We will explore a better solution.
Signed-off-by: Kathryn Baldauf <k_baldauf@apple.com>