[Path] Fix Waterline error due to invalid arguments in getOffsetArea() calls

[Russ4262]

This commit fixes the error reported in the forum at Re: Waterline milling update.

This error was introduced when a contributor replaced the extractFaceOffset() method from the PathSurfaceSupport.py module with an improved getOffsetArea() function in the PathUtils.py module. The two instances of the improved getOffsetArea() calls here in this fix did not get corrected (updated argument lists) when that improvement was originally made. This fix corrects the argument lists in the two function calls.

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[freecadci]

for feature branch PR_5097. Pipeline #384021798 was triggered at c35e44d. All CI branch pipelines.