Bug 1774144 - mach: Only report physical cores if they could be determined. r=firefox-build-system-reviewers,ahochheiden

As per the docs:

> Return the number of logical CPUs in the system (same as os.cpu_count in Python 3.4) or None if undetermined.
> [...] On OpenBSD and NetBSD psutil.cpu_count(logical=False) always return None

Glean tries to coerce values to the expected type. `None` cannot be
coerced to an integer, so this blows up.
We conditionally report that value now only if we can properly detect
one.

Differential Revision: https://phabricator.services.mozilla.com/D149201

build/mach_initialize.py

@@ -541,7 +541,8 @@ def _finalize_telemetry_glean(telemetry, is_bootstrap, success):
         # psutil may not be available (we may not have been able to download
         # a wheel or build it from source).
         system_metrics.logical_cores.add(logical_cores)
-        system_metrics.physical_cores.add(physical_cores)
+        if physical_cores is not None:
+            system_metrics.physical_cores.add(physical_cores)
         if memory_total is not None:
             system_metrics.memory.accumulate(
                 int(math.ceil(float(memory_total) / (1024 * 1024 * 1024)))