'make elyra-image' and 'make kf-notebook-image' fail

[ptitzler]

Describe the issue

make elyra-image and make kf-notebook-image fail if one tries to build them in an official release setting.

$ make elyra-image
cp etc/docker/elyra/Dockerfile build/docker/Dockerfile
cp etc/docker/elyra/start-elyra.sh build/docker/start-elyra.sh
cp etc/docker/elyra/requirements.txt build/docker/requirements.txt
if [ "3.10.1" == "dev" ]; then \
		cp dist/elyra-$(grep __version__ elyra/_version.py | cut -d"\"" -f2)-py3-none-any.whl build/docker/; \
  	fi
docker buildx build \
        --progress=plain \
        --output=type=docker \
		--tag docker.io/elyra/elyra:3.10.1 \
		--tag quay.io/elyra/elyra:3.10.1 \
		--build-arg TAG=3.10.1 \
		--build-arg ELYRA_VERSION=$(grep __version__ elyra/_version.py | cut -d"\"" -f2) \
		build/docker/;
#1 [internal] load build definition from Dockerfile
#1 transferring dockerfile: 1.75kB 0.0s done
#1 DONE 0.1s

#2 [internal] load .dockerignore
#2 DONE 0.0s

#2 [internal] load .dockerignore
#2 transferring context: 2B done
#2 DONE 0.0s

#3 resolve image config for docker.io/docker/dockerfile:experimental
#3 DONE 7.4s

#4 docker-image://docker.io/docker/dockerfile:experimental@sha256:600e5c62eedff338b3f7a0850beb7c05866e0ef27b2d2e8c02aa468e78496ff5
#4 ...

#5 [internal] load metadata for docker.io/jupyterhub/k8s-singleuser-sample:1.2.0
#5 DONE 0.0s

#6 [1/6] FROM docker.io/jupyterhub/k8s-singleuser-sample:1.2.0
#6 CACHED

#7 [internal] load build context
#7 transferring context: 1.14kB done
#7 DONE 0.0s

#8 [2/6] COPY elyra-3.10.1-py3-none-any.whl requirements.txt ./
#8 ERROR: "/elyra-3.10.1-py3-none-any.whl" not found: not found

#4 docker-image://docker.io/docker/dockerfile:experimental@sha256:600e5c62eedff338b3f7a0850beb7c05866e0ef27b2d2e8c02aa468e78496ff5
------
 > [2/6] COPY elyra-3.10.1-py3-none-any.whl requirements.txt ./:
------
error: failed to solve: failed to compute cache key: "/elyra-3.10.1-py3-none-any.whl" not found: not found
make: *** [elyra-image] Error 1

The reason is that the Dockerfile (e.g.
https://github.com/elyra-ai/elyra/blob/main/etc/docker/elyra/Dockerfile#L24-L26) the wheel to be always present in the local file system.

To Reproduce
Steps to reproduce the behavior:

git pull --rebase
git checkout tags/vX.Y.Z
make container-images

Expected behavior
A clear and concise description of what you expected to happen.

Deployment information
Describe what you've deployed and how:

• Elyra version: 3.10