test/jdk/java/io/FileOutputStream/UnreferencedFOSClosesFd.java fails with "raw fd count wrong"

Test failed in latest CI job:

final count of open file descriptors: 44
----------System.err:(13/889)----------
java.lang.AssertionError: raw fd count wrong: expected: 45, actual: 44
at UnreferencedFOSClosesFd.main(UnreferencedFOSClosesFd.java:158)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:569)
at com.sun.javatest.regtest.agent.MainWrapper$MainThread.run(MainWrapper.java:115)
at java.base/java.lang.Thread.run(Thread.java:831)