20797: Run microdnf with --assumeyes

20797: Run microdnf with --assumeyes

`docker run --rm -ti rockylinux:8-minimal microdnf --help` says,

> The "--assumeyes" option is turned on by default.

However, that behavior apparently changes in a future version:
<https://github.com/rpm-software-management/microdnf/pull/97>,
microdnf commit ca778a0b34c5e15b5b0de1e0af0f8892280fc0c2.

Passing `--assumeyes` provides more consistency and will help keep the
code working in later releases.

Arvados-DCO-1.1-Signed-off-by: Brett Smith <brett.smith@curii.com>