fix: gracefully handle missing manifest revisions during imports

See merge request !977

fix: gracefully handle soft-deleted repositories during imports

See merge request !975

fix: gracefully handle unsupported schema v1 manifests during imports

See merge request !978

## [3.39.1](v3.39.0-gitlab...v3.39.1-gitlab) (2022-04-20)

### Bug Fixes

* gracefully handle missing manifest revisions during imports ([dc31a557](dc31a557))
* gracefully handle soft-deleted repositories during imports ([f74d5e2e](f74d5e2e))
* gracefully handle unsupported schema v1 manifests during imports ([7e408f88](7e408f88))