ci: start kani test without waiting for build

The kani test does not use the pre-built firecracker binaries, as kani
does static analysis, and does not execute binaries. Thus, do not have
the kani test block on compilation finishing.

Signed-off-by: Patrick Roy <[email protected]>

Author: roypat

.buildkite/common.py

@@ -314,8 +314,9 @@ def build_group(self, *args, **kwargs):
 
         https://buildkite.com/docs/pipelines/group-step
         """
+        decorate = kwargs.pop("decorate", True)
         combined = overlay_dict(self.per_instance, kwargs)
-        return self.add_step(group(*args, **combined))
+        return self.add_step(group(*args, **combined), decorate=decorate)
 
     def build_group_per_arch(self, *args, **kwargs):
         """

.buildkite/pipeline_pr.py

@@ -58,10 +58,12 @@
         platforms=[("al2", "linux_5.10")],
         timeout_in_minutes=300,
         **DEFAULTS_PERF,
+        decorate=False,
     )
     # modify Kani steps' label
     for step in kani_grp["steps"]:
         step["label"] = "🔍 Kani"
+    kani_grp["depends_on"] = None
 
 if run_all_tests(changed_files):
     pipeline.build_group(