gh-148841: Fix test_posix on FreeBSD 15 with zfs filesys

Handle EOPNOTSUPP as well as EINVAL in this case.

Author: neek78

Lib/test/test_os/test_posix.py

@@ -415,7 +415,8 @@ def test_posix_fallocate(self):
             if inst.errno == errno.EINVAL and sys.platform.startswith(
                 ('sunos', 'freebsd', 'openbsd', 'gnukfreebsd')):
                 raise unittest.SkipTest("test may fail on ZFS filesystems")
-            elif inst.errno == errno.EOPNOTSUPP and sys.platform.startswith("netbsd"):
+            elif inst.errno == errno.EOPNOTSUPP and sys.platform.startswith(
+                    ("netbsd", "freebsd")):
                 raise unittest.SkipTest("test may fail on FFS filesystems")
             else:
                 raise