metropolis/node: remove genrule image_gcp

This is currently very flaky and we dont use it anyway

Change-Id: Idf91cdc3f45da11635a8ee78617d209665a5bbc7
Reviewed-on: https://review.monogon.dev/c/monogon/+/2028
Reviewed-by: Lorenz Brun <lorenz@monogon.tech>
Tested-by: Jenkins CI
diff --git a/metropolis/node/BUILD.bazel b/metropolis/node/BUILD.bazel
index a62d8aa..fe48cce 100644
--- a/metropolis/node/BUILD.bazel
+++ b/metropolis/node/BUILD.bazel
@@ -167,30 +167,6 @@
     ],
 )
 
-# Create a tar.gz of the image, suitable for importing to GCP as a custom image.
-# (see https://cloud.google.com/compute/docs/import/import-existing-image#create_image_file)
-#
-# We can't use Bazel's "pkg_tar" rule because it insists on adding a "./" prefix to the
-# file name inside the archive, which is not compatible with GCP's importer.
-genrule(
-    name = "image_gcp",
-    srcs = [
-        ":image",
-    ],
-    outs = [
-        "node.tar.gz",
-    ],
-    cmd = """
-    # make it reproducible and fast (it doesn't compress well anyway)
-    export GZIP="--no-name --fast"
-
-    ln -rs $< $(@D)/disk.raw  # GCP insists it be called "disk.raw"
-
-    cd $(@D)
-    tar --format=oldgnu --mtime='1970-01-01' -Sczhf node.tar.gz disk.raw
-    """,
-)
-
 genrule(
     name = "swtpm_data",
     outs = [