Update disk image. (iree-org#17985)

Last update broke the image b/c the runner-root directory was copied
from the instance.

Testing a new image, same as previous but without runner-root. Only
testing CPU first.

Signed-off-by: Nancy Yuen <yuenn@google.com>

build_tools/github_actions/runner/gcp/create_templates.sh

@@ -18,7 +18,7 @@ DRY_RUN="${DRY_RUN:-0}"
 TESTING_SELF_DELETER="${TESTING_SELF_DELETER:-0}"
 
 GPU_IMAGE="${GPU_IMAGE:-github-runner-gpu-2024-07-18-011326}"
-CPU_IMAGE="${CPU_IMAGE:-github-runner-cpu-2024-07-17-203409}"
+CPU_IMAGE="${CPU_IMAGE:-github-runner-cpu-2024-07-20-012014}"
 ARM64_IMAGE="${ARM64_IMAGE:-github-runner-arm64-2024-07-18-001959}"
 DISK_SIZE_GB="${DISK_SIZE_GB:-1000}"