T6311: Add curl, ca-certificates and unzip to apertis-test-cases docker image

We are moving to downloading and extracting artifacts for each branch in the test-cases CI pipeline, rather than looping through the git branches and generating the test cases per branch. In order to do this we need curl to download the artifacts, ca-certificates to validate the server certificate and unzip to extract the artifact.

Signed-off-by: Martyn Welch martyn.welch@collabora.com