Add core benchmarks dir, fix core pseudo-component, use simulation mode

- Move scheduler/loop/helpers benchmarks to tests/benchmarks/components/core/
- Add random_float and random_uint32 benchmarks (from ol.yaml)
- Fix core pseudo-component crash: skip components where get_component()
  returns None when adding dependencies to config
- Use CodSpeed simulation mode (CPU instruction counting) for reproducible
  CI results instead of walltime

script/test_helpers.py

@@ -248,7 +248,9 @@ def compile_and_get_binary(
             domain_list = config.setdefault(domain, [])
             CORE.testing_ensure_platform_registered(domain)
             domain_list.append({CONF_PLATFORM: component})
-        else:
+        # Skip "core" — it's a pseudo-component handled by the build
+        # system, not a real loadable component (get_component returns None)
+        elif get_component(component_name) is not None:
             config.setdefault(component_name, [])
 
     # Register platforms from the extra config (benchmark.yaml) so