Use Github release MCR files for fetching CAT12 binaries

[jhuguetn]

As seen in ChristianGaser/cat12#25, from now on Github CAT12 repo releases will be apparently including the binaries of the standalone version of CAT12 as well. Consider using it as source for fetching stable CAT12 MCR versions in our Docker image.

[jhuguetn]

This is not the case anymore with CAT r2665, which is available at CAT12.9_R2023b_MCR_Linux.zip but not under Github release binaries.