[processing] "WARNING Cannot open test.tif ().()" message displayed when running some algorithms

[agiudiceandrea]

What is the bug or the crash?

The following warning messages are displayed in the OGR tab of the Log Messages panel when running some algorithms that can have multiple input layers (QgsProcessingParameterMultipleLayers) as input:

WARNING    Cannot open C:/TMP/test.tif ().()
WARNING    Cannot open C:/TMP/test.tif ().()

It looks like this issue (probably in parameterAsLayerList) is similar to the ones already previously reported (https://github.com/qgis/QGIS/issues/57914, https://github.com/qgis/QGIS/issues/57758, https://github.com/qgis/QGIS/issues/57494) and fixed (https://github.com/qgis/QGIS/pull/57963, https://github.com/qgis/QGIS/pull/57772, https://github.com/qgis/QGIS/pull/57508) by @nyalldawson

Steps to reproduce the issue

For example:

1. Open the "Tile index" GDAL processing algorithm's GUI
2. Select any input layer
3. Run the algorithm with default parameters
4. See the warning messages in the OGR tab of the Log Messages panel

Versions

QGIS 3.34.9, QGIS 3.38.1, QGIS 3.39.0-Master f4005f7e5f on Windows 10.

Supported QGIS version

• [X] I'm running a supported QGIS version according to the roadmap.

New profile

• [X] I tried with a new QGIS profile

Additional context

No response