AST-1640 Add 'scan' stage for SKAO finaliser template
CI pipelines at the SKAO mirror failed because of a missing 'scan' stage. The SKAO finaliser template now includes dependency scanning jobs, which require this stage. CI at Astron will ignore this stage, since it has no jobs.
Like the SKAO Python example template, the 'scan' stage is between the 'publish' and 'pages' stages.
Edited by Maik Nijhuis