fix(ci): timezone.utc for Python 3.10 + restrict pytest to tests/ [skip release]

- telemetry.py used datetime.UTC (3.11+), breaking import on Python 3.10 across all modules that import telemetry; use timezone.utc (universal).

- Add testpaths=[tests] so the bare pytest in CI no longer collects the factorization-lab/ and primality-test/ companion projects (which have their own setup).

Author: TNFR AI Agent

pyproject.toml

@@ -290,6 +290,7 @@ exclude = [
 
 [tool.pytest.ini_options]
 pythonpath = ["src"]
+testpaths = ["tests"]
 addopts = "-m 'not slow'"
 markers = [
   "slow: marks tests as slow (deselect with '-m \"not slow\"')",

src/tnfr/metrics/telemetry.py

@@ -55,7 +55,7 @@
 import json
 import time
 from dataclasses import asdict, dataclass
-from datetime import UTC, datetime
+from datetime import datetime, timezone
 from pathlib import Path
 from typing import Any, Iterable, Mapping, MutableMapping
 
@@ -333,7 +333,7 @@ def _compute() -> None:
 
         # Use timezone-aware UTC to avoid deprecation of datetime.utcnow()
         event = TelemetryEvent(
-            t_iso=datetime.now(UTC).isoformat(timespec="seconds"),
+            t_iso=datetime.now(timezone.utc).isoformat(timespec="seconds"),
             t_epoch=time.time(),
             step=step,
             operator=operator,