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This reverts commit c36895eb.

Until GHC, LLVM, or qemu-user are more stable, just let GHC be installed
from our binary bootstrap package generated in the
https://gitlab.james.tl/nest/tools/ghc project.

This reverts commit dadf6f41.

ghc: Add 9.0.1 bootstrap package for amd64

PGO can't be used under qemu-user and it doesn't build in an unprivileged
container (missing ptrace) and it really does take too long to compile
for only slight gains.

This reverts commit b0c1879d.