[bazel] mark e2e_bootup_no_rom_ext_signature test as broken

The timeout is very long, but not duplicated with bazel so it's timing
out. I don't know if that's expected behavior but the test also relies
on the mask-rom bitstream which might require that the CI be made to
exclude things that depend on the mask rom instead of including things
that rely on the test rom

Signed-off-by: Drew Macrae <drewmacrae@google.com>
diff --git a/sw/device/silicon_creator/mask_rom/BUILD b/sw/device/silicon_creator/mask_rom/BUILD
index d9a678a..f84603a 100644
--- a/sw/device/silicon_creator/mask_rom/BUILD
+++ b/sw/device/silicon_creator/mask_rom/BUILD
@@ -330,6 +330,7 @@
             "--exit-failure='PASS!'",
         ],
         bitstream = "//hw/bitstream:mask_rom",
+        tags = ["broken"],
     ),
     signed = False,
     targets = ["cw310"],