gh-148853: Catch PermissionError in test in_systemd_nspawn_sync_suppressed() (GH-148854)

/run/ on my FreeBSD install is not readable causing failing test.
(cherry picked from commit 35ce2e5)

Co-authored-by: Nick Begg <nick@stunttruck.net>
Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com>

Author: 2 people

Lib/test/support/__init__.py

@@ -3073,7 +3073,7 @@ def in_systemd_nspawn_sync_suppressed() -> bool:
         with open("/run/systemd/container", "rb") as fp:
             if fp.read().rstrip() != b"systemd-nspawn":
                 return False
-    except FileNotFoundError:
+    except (FileNotFoundError, PermissionError):
         return False
 
     # If systemd-nspawn is used, O_SYNC flag will immediately

Misc/NEWS.d/next/Tests/2026-04-24-01-38-56.gh-issue-148853._uM4_Q.rst

@@ -0,0 +1,2 @@
+Fix tests failing on FreeBSD in test.support's
+in_systemd_nspawn_sync_suppressed()  due to unreadable /run directory.