tst_opcua:AbsoluteNodeTest is flaky on Mac

Recent test runs indicate that tst_opcua:AbsoluteNodeTest is flaky.
Flakiness has been seen on MacOS_10_14, MacOS_10_15, MacOS_11 ARM, MacOS_12 intel, MacOS_12 ARM.

Example of a fail:
agent:2022/06/16 20:37:54 build.go:394: 4: FAIL! : opcua::AbsoluteNodeTest: open62541: Assign int value to double node::test_nodeTest() Compared values are not the same
agent:2022/06/16 20:37:54 build.go:394: 4: Actual (): 2
agent:2022/06/16 20:37:54 build.go:394: 4: Expected (): 1
agent:2022/06/16 20:37:54 build.go:394: 4: Loc: [/Users/qt/work/qt/qtopcua/tests/auto/declarative/AbsoluteNodeTest.qml(440)]

Full log: https://testresults.qt.io/logs/qt/qtopcua/1618136a38e2c5e22f62418a223535ae0e8f5c6c/MacOSMacOS_12arm64MacOSMacOS_12arm64Clangqtci-macos-12-arm64TestOnly/fd6e385eded9d88268d61c8758f1988ec576efe9/test_1655134683/log.txt.gz

There is a bug, QTBUG-103386, that causes that this flakiness is not visible in the flakyness Grafana dashboards.