fix #121906: footer tooltip does not disappear (takes too long)

[SKefalidis]

Resolves: https://musescore.org/en/node/121906

The default value of tooltip duration (-1) leads to an automatic calculation of the duration of the tooltip. This causes the tooltip to stay on screen for too long (since it's pretty big). I changed the value to 5 seconds, which is enough to read most things and at the same time is not obstructing the user.

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