Fix image related workflows

[adrianchiris]

docker buildx is unable to cope with upper case
letters in image repository.

The following is seen in logs of push-main workflow:

error: invalid tag
"ghcr.io/Mellanox/multi-networkpolicy-tc:latest-amd64":
repository name must be lowercase

To cope with this, convert repository name to lowercase

Signed-off-by: Adrian Chiris [email protected]

[adrianchiris]

Thats what im seeing in logs:

/usr/bin/docker buildx build --file ./Dockerfile --iidfile /tmp/docker-build-push-bnEWUq/iidfile --label org.opencontainers.image.title=multi-networkpolicy-tc --label org.opencontainers.image.description=Linux Traffic Control (TC) based implementation of Kubernetes NPWG MultiNetworkPolicy API --label org.opencontainers.image.url=https://github.com/Mellanox/multi-networkpolicy-tc --label org.opencontainers.image.source=https://github.com/Mellanox/multi-networkpolicy-tc --label org.opencontainers.image.version=main --label org.opencontainers.image.created=2022-07-21T18:50:34.068Z --label org.opencontainers.image.revision=a81032c2861cd542541d116d3dde368b9f0dbdd3 --label org.opencontainers.image.licenses=Apache-2.0 --secret id=GIT_AUTH_TOKEN,src=/tmp/docker-build-push-bnEWUq/tmp-2635-bCsf4Q9odx8r --tag ghcr.io/Mellanox/multi-networkpolicy-tc:latest-amd64 --metadata-file /tmp/docker-build-push-bnEWUq/metadata-file --push https://github.com/Mellanox/multi-networkpolicy-tc.git#a81032c2861cd542541d116d3dde368b9f0dbdd3
error: invalid tag "ghcr.io/Mellanox/multi-networkpolicy-tc:latest-amd64": repository name must be lowercase
Error: buildx failed with: error: invalid tag "ghcr.io/Mellanox/multi-networkpolicy-tc:latest-amd64": repository name must be lowercase

tested the fix in a separate branch in this repo as my fork is lowercase only