Ah, yes. The failing test prevents the upload of the binary as the CI assumes the generated FTL binary is broken. It seems verteiltesysteme.net is not available right now. Their entire infrastructure (134.91.78.139, 134.91.78.141, 2001:638:501:8efc::139, 2001:638:501:8efc::141) seems to be down.
This has already been discussed in the German part of this forum and is one of the top Google results for said domain today: