Update builder images. Yay for GHC's improved cross-compiler support!

builders/linux.riscv64/build

@@ -1,21 +1,14 @@
 #!/bin/sh
 set -xe
-IFS=';'
 {
-  mkdir -p /tmp/scratch
-  cd /tmp/scratch
   tar xzv --strip-components=1
   chmod +x striptests && ./striptests
-  # Use a freeze file to ensure we use the same dependencies we cached during
-  # the docker image build. We don't want to spend time compiling anything new.
-  cp /etc/cabal.project.freeze .
   mkdir "$TARGETNAME"
-  # Retry in case of random segfault
-  scutil retry 3 cabal build --enable-executable-static
+  ( IFS=';'; cabal build $CABALOPTS --enable-executable-static )
   find . -name shellcheck -type f -exec mv {} "$TARGETNAME/" \;
   ls -l "$TARGETNAME"
   "$TARGET-strip" -s "$TARGETNAME/shellcheck"
   ls -l "$TARGETNAME"
-  "$TARGETNAME/shellcheck" --version
+  "qemu-${TARGET%%-*}-static" "$TARGETNAME/shellcheck" --version
 } >&2
 tar czv "$TARGETNAME"