Fix weekly image download cron job for 2.x images (#2438)

Need to use the full path for unzip when running a systemd job.

Author: clundin25

.gitignore

@@ -28,3 +28,4 @@ hw/fpga/vivado*.log
 
 # libcaliptra build artifacts
 libcaliptra/libcaliptra.a
+ci-tools/host-runner/secrets/

ci-tools/host-runner/configuration.nix

@@ -58,7 +58,7 @@ let
 
       for VARIANT in "caliptra-fpga-image-core-2.0" "caliptra-fpga-image-core-2.1" "caliptra-fpga-image-subsystem-2.0" "caliptra-fpga-image-subsystem-2.1"; do
           ${rtool}/bin/rtool download_artifact 379559 40993215 fpga-image.yml $VARIANT main-2.x > $VARIANT.zip
-          unzip $VARIANT.zip
+          ${pkgs.unzip}/bin/unzip $VARIANT.zip
           (mv $VARIANT.img $VARIANT.img.old || true)
           mv image.img $VARIANT.img
           rm $VARIANT.zip