A horizontal frame with width=0 is not saved correctly

Issue type

Engraving bug (incorrect score rendering)

Bug description

A horizontal frame with a width = 0 has its width not correctly saved.
Setting the width to 0 is possible and rendered correctly. Nevertheless after saving and reopening, the width is back to its default value: 5 (and rendered accordingly).

Steps to reproduce

1. Add an horizontal frame in the score
2. Set its width to 0
3. Save and close the score.
4. Reopen the score
5. The frame has a width of 5

Screenshots/Screen recordings

Score with 2 frames:

1. between measure 1-2. With a zero width on the main score, and a non-zero width on the part.
2. between measure 2-3. With a non-zero width on the main score, and a zero width on the part.

As saved/Expected

Main score

Part

As reopened

Main score

Part

MuseScore Version

4.2.1

Regression

Yes, this used to work in MuseScore 3.x and now is broken

Operating system

Windows10

Additional context

Regression:

• It used to work with MU 3.6
• A correct 3.6 file is not loaded correctly with MU4