Unable to delete files .shp and .dbf using python code (removeMapLayers, deleteShapeFile)

[DG-85]

Describe the bug

It looks like the simple code below does not work as expected. In my plugin "deleteShapeFile" results always in "False".
All files will be deleted except .shp and .dbf. They are somehow still in use.

The same problem is also mentioned here: https://gis.stackexchange.com/questions/376765/unable-to-delete-shp-and-dbf-files-from-directory-when-on-canvas-pyqgis

How to Reproduce

    aLayer = self.iface.activeLayer()                            
    shp = str(aLayer.publicSource())                             
    j=shp.find("|")                                              
    if j > -1:                                                   
     shp = shp[:j]                                               
    QgsProject.instance().removeMapLayers([aLayer.id()])         
    ret = QgsVectorFileWriter.deleteShapeFile(shp)               
    QMessageBox.warning(self.iface.mainWindow(),"ret", str(ret) )

QGIS and OS versions
3.14.1-Pi and Windows 10 (64-bit)

Additional context

[gioman]

@DG-85you should ask in the developers ML if you are doing it right, rather than assuming that is a bug (maybe it is, but better check first with the gurus).

[alexbruy]

Can't reproduce on both Linux and Windows.

[github-actions]

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[github-actions]

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