This fixes a problem when installing the packages from local files instead of
from the package repository. The current packages had a strong dependency set
in both directions (`docker-ce-cli` requires `docker-scan-plugin`, and vice-
versa). This caused a circular dependency, which could not be resolved when
trying to install the packages offline (from downloaded rpm files);

    yum install ./docker-scan-plugin-0.17.0-3.fc35.x86_64.rpm
    Last metadata expiration check: 1:09:40 ago on Tue Mar  8 08:30:47 2022.
    Error:
    Problem: conflicting requests
    - nothing provides docker-ce-cli needed by docker-scan-plugin-0.17.0-3.fc35.x86_64
      (try to add '--skip-broken' to skip uninstallable packages)

    yum install ./docker-ce-cli-20.10.13-3.fc35.x86_64.rpm
    Last metadata expiration check: 1:10:23 ago on Tue Mar  8 08:30:47 2022.
    Error:
    Problem: conflicting requests
    - nothing provides docker-scan-plugin(x86-64) needed by docker-ce-cli-1:20.10.13-3.fc35.x86_64
      (try to add '--skip-broken' to skip uninstallable packages)

This patch

- changes the `docker-scan-plugin` to `Enhances
- changes the `docker-ce-cli` package to mark the scan plugin as `Recommends`,
  with the exception of CentOS/RHEL 7, which do not yet support weak dependencies.
  For those, we continue to use `Requires`.

The `Recommends` dependency should be installed by default, but users can opt-out
by passing `--setopt=install_weak_deps=False` to `dnf`.

Signed-off-by: Sebastiaan van Stijn <[email protected]>
(cherry picked from commit 51098f9)
Signed-off-by: Sebastiaan van Stijn <[email protected]>