ci: use rootfs image with openmodelica and gfortran pre-installed

Author: Anant Thazhemadam

.buildkite/launch_benchmarks.yml.signature

@@ -1,2 +1,3 @@
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.buildkite/run_benchmark.yml

@@ -19,8 +19,8 @@ steps:
       - JuliaCI/julia#v1:
           version: "1.10"
       - staticfloat/sandbox:
-          rootfs_url: "https://github.com/thazhemadam/openmodelica-rootfs-image/releases/download/v1.23.0/rootfs-openmodelica-v1.23.0.amd64.tar.gz"
-          rootfs_treehash: "82970243dc4f188e599a976abc20951f4aba2912"
+          rootfs_url: "https://github.com/thazhemadam/ScimlBenchmarks-rootfs-image/releases/download/rootfs-image/rootfs-script.amd64.tar.gz"
+          rootfs_treehash: "943bde824554f0afad5a939341f05e3bdb393051"
           uid: 1000
           gid: 1000
           workspaces: