fix(libkernel): remove a watched descriptor's events before dup2 takes its positioned lock on Windows

dup2 called EqueueDescriptorClosed(to) while holding the positioned-transfer lock of the descriptor, and the in-flight measurement it waits for needs that lock for its sceKernelLseek, so dup2 onto a watched descriptor deadlocked. The events are removed first, before the lock is taken.

core/libs/prx/libkernel/File/src/Stdio.cpp

@@ -879,13 +879,13 @@ int APS5_VABI dup2_nid_postfix(int from, int to) {
     if (from == to) return to;
     if (to == 1) PreserveHostStandardOutput();
     if (to == 2) PreserveHostStandardError();
+    EqueueDescriptorClosed(to);
     auto positioned = File::LockPositionedTransfer(to);
     auto* const standard = HostStandardHandle_nid_no_patch(to);
     int duplicated = File::ReplaceSharedMemoryDescriptor_nid_no_patch(from, to);
     if (duplicated == -2) duplicated = WithoutParameterHandler([from, to] { return ::_dup2(from, to); });
     KeepStandardHandle_nid_no_patch(to, standard);
     if (duplicated != 0) return PosixFailure(SceErrorFromErrno(errno) & 0xffff);
-    EqueueDescriptorClosed(to);
     GuestSockets::Forget(to);
     File::ForgetDirectoryDescriptor(to);
     File::DuplicateDirectoryDescriptor(from, to);