Report available CPU cores with cpu_info (#160)

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

Author: jpintar

src/session_info2/_pu.py

@@ -4,6 +4,7 @@
 import os
 import platform
 import shutil
+import sys
 from multiprocessing import cpu_count
 from pathlib import WindowsPath
 from subprocess import CalledProcessError, run
@@ -12,7 +13,14 @@
 def cpu_info() -> str:
     """Get CPU info."""
     proc = platform.processor() or None
-    return f"{cpu_count()} logical CPU cores{f', {proc}' if proc else ''}"
+    total_cores = cpu_count()
+    if sys.version_info >= (3, 13):
+        avail_cores = os.process_cpu_count()
+    elif platform.system() == "Linux":
+        avail_cores = len(os.sched_getaffinity(0))
+    else:
+        avail_cores = total_cores
+    return f"{avail_cores}/{total_cores} logical CPU cores{f', {proc}' if proc else ''}"
 
 
 def gpu_info() -> tuple[str, ...]: