[Customization] Reload user defined toolbar actions only one time

[troopa81]

Description

Fix unreported issue: Hidden actions from user defined toolbar are still visible.

It's already done in updateActionVisibility, we don't need to do it twice

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[github-actions]

🪟 Windows Qt6 builds

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(Built from commit 1db7c42)

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[troopa81]

@signedav Do you mind reviewing ? this a #66483 follow up

[signedav]

Part with the redundant loop makes sense. Maybe add the unrelated icon fix to the PR description or remove it when not part of the implementation.

[troopa81]

Part with the redundant loop makes sense. Maybe add the unrelated icon fix to the PR description or remove it when not part of the implementation.

I removed the setIcon part