Remove adding sha256 sum for CI container images (#207)

Each time when there is added new feature to this project, the
SHA256 sum needs to be updated just to pass the CI.
The digest is taken also from "latest" container image, so
there is no need to pin digest to an image which disappear after
a while.

Signed-off-by: Daniel Pawlik <dpawlik@redhat.com>

Author: danpawlik

oci/Containerfile

@@ -12,7 +12,7 @@ RUN make build \
     && curl -LO ${PULUMI_URL} \
     && tar -xzvf pulumi-${PULUMI_VERSION}-linux-x64.tar.gz
 
-FROM quay.io/centos/centos:stream9@sha256:5bd57c6d9d1da7c41f772b1663ca342a66fd2131ff0895bc929d828b8aa16a30
+FROM quay.io/centos/centos:stream9
 
 LABEL MAINTAINER "CRC <devtools-cdk@redhat.com>"