Optimise the check setup part

[vaitkus]

The current version of the action takes an extremely long time to setup the checks versus actually running them (and also runs quite long in comparison to the other dictionary checks). Probably up to 95% of the time is spent setting up the cod-tools repository. At one time this type of setup was preferred over the installation of the cod-tools Debian package due to the fast pace of development of the cif_ddlm_dic_check and ddlm_validate utilities. However, in recent years this has significantly slowed down, so it might make sense to switch back to the package approach once Debian 13 is released (it will contain a relatively recent cod-tools version).

Alternatively, the current installation from the source could be further optimised, e.g. by avoiding the installation of packages that are not relevant to these specific checks, but this will require some testing to track down the dependencies.

[jamesrhester]

Agree that switching to a standard distribution cod-tools would save a lot of time once it is released. Also, would using Github cache help here?

[vaitkus]

My educated guess would be that to make proper use of GitHub caching the action would need to be reorganised to conduct more work outside the entrypoint.sh script. Because now the downloaded dictionaries can definitely be cached, but not the cod-tools package as this is recreated each time the Docker image is recreated. However, I might as well be missing something obvious here.