[INTERNAL] Fixes llvm ci builds.
[INTERNAL] Fixes llvm ci builds.

Uses downloaded binaries of llvm toolchain to temporarily work around the unavailable llvm package provider.

bestrauc/seqan,bestrauc/seqan,xenigmax/seqan,bestrauc/seqan,bestrauc/seqan,bestrauc/seqan,xenigmax/seqan,xenigmax/seqan,xenigmax/seqan,xenigmax/seqan,bestrauc/seqan,bestrauc/seqan,xenigmax/seqan,bestrauc/seqan,xenigmax/seqan,xenigmax/seqan