[Bug]: The `QScrollBar` for the account list context menu renders over the accounts' overflow menus' buttons' icons.

### Before submitting, please verify the following:

1. [x] This is a **bug**, not a question or a configuration issue.

1. [x] This issue is **not** already reported on Github (I've searched it).

1. [x] Nextcloud Server and Desktop Client are **up to date**. See [Server Maintenance and Release Schedule](https://github.com/nextcloud/server/wiki/Maintenance-and-Release-Schedule) and [Desktop Releases](https://nextcloud.com/install/#install-clients) for supported versions.

1. [x] I agree to follow Nextcloud's [Code of Conduct](https://nextcloud.com/contribute/code-of-conduct/)

### Bug description

As the undermentioned screenshot depicts, the scroll bar renders over the hamburger menu icon of the button which invokes the account-specific context menu:


### Steps to reproduce

1. Install https://download.fedoraproject.org/pub/fedora/linux/releases/40/Spins/x86_64/iso/Fedora-KDE-Live-x86_64-40-1.14.iso

1. Install https://fedora.pkgs.org/40/fedora-updates-x86_64/nextcloud-client-3.13.4-2.fc40.x86_64.rpm.html

1. Add accounts:

1. 1 x `rokejulianlockhart@de.tab.digital`

1. 1 x `rokejulianlockhart@murena.io`

1. 1 x `beedellrokejulianlockhart@murena.io`

1. 1 x `RokeJulianLockhart@my.opendesktop.org`

1. 1 x `RokeJulianLockhart@nch.pl`

1. 1 x `BEEDELLROKEJULIANLOCKHART@OUTLOOK.COM@nextcloud05.webo.cloud`

1. 1 x `RokeJulianLockhart@wim.nl.tab.digital`

1. Attempt to access the context menu, as aforedepicted.

### Expected behavior

The scroll bar shouldn't render atop them.

### Which files are affected by this bug

No files are affected.

### Operating system

Linux

### Which version of the operating system you are running

https://download.fedoraproject.org/pub/fedora/linux/releases/40/Spins/x86_64/iso/Fedora-KDE-Live-x86_64-40-1.14.iso

### Package

Distro package manager

### Nextcloud Server version

Multiple:

Scan | Server
------------------------------------------------------------------------|-------------------------------
https://scan.nextcloud.com/results/ec393317-f5f1-4a83-b5f0-b6ea8f16ea1e | https://de.tab.digital
https://scan.nextcloud.com/results/9e38a4f6-f9c2-4560-a6db-fe8d462af9a5 | https://murena.io
https://scan.nextcloud.com/results/6df2873d-2a9e-422c-88ef-6b3619d4e6f0 | https://my.opendesktop.org
https://scan.nextcloud.com/results/b022f479-6ce5-4c23-b315-756eef047b73 | https://nch.pl
https://scan.nextcloud.com/results/aaf6cce4-969a-44ec-86a3-46c0cbf8059c | https://nextcloud05.webo.cloud
https://scan.nextcloud.com/results/e251f480-ae2b-4298-a7c0-2eee1336012d | https://wim.nl.tab.digital

### Nextcloud Desktop Client version

https://fedora.pkgs.org/40/fedora-updates-x86_64/nextcloud-client-3.13.4-2.fc40.x86_64.rpm.html

### Is this bug present after an update or on a fresh install?

Unknown.

### Are you using the Nextcloud Server Encryption module?

Unknown.

### Are you using an external user-backend?

Unknown.

### Nextcloud Server logs

I am unable to provide these.

### Additional info

https://github.com/nextcloud/desktop/issues/7268#issuecomment-2394789834

Start by reproducing the account list context menu on Fedora KDE with several accounts and inspect the QScrollBar and account-specific overflow buttons. Done means the scrollbar no longer renders over the buttons' hamburger icons; the issue names no affected files or tests, so locating the relevant UI code will require repository research.

Written by the indexing model from the issue text.