[Bug]: installer unable to install on a partition with an existing filesystem

### Kernel

6.18.42-1-cachyos-lts

### Desktop Environment / Window Manager

KDE Plasma

### CPU

Intel(R) Core(TM) i7-8550U CPU @ 1.80GHz

### GPU / Driver

intel

### Description

i try cachyos in an vm. i prepared the storage with the desired partitions (efi, linux root 1, linux root 2, home). i use the option in the installer to choose the partitionm to install cachyos to (very neat! thank you for that!). first installation failed due to other reasons but left a btrfs filesystem in the 3rd partition. when i retried the installation the installer failed because it could not create a filesystem in the third partition.

### Steps to Reproduce

# roughly its like this:

2. use a pre partitioned disk
3. create a btrfs filesystem on the install root partition
4. run the installer
5. choose to install into a choosen partition (the one you creted in step 2)
6. continue the installer

### Expected Behavior

cachyos installer should wipe the filesystem signiture to let `mkfs` run successfully or give it a force option.

### Actual Behavior

mkfs fails because the partition contains a filesystem already

### Logs / Error Messages

example.org

### Additional Context

my log was lost, if really required i can redo the installation procedure and try to get the log

Start by reproducing the installation flow with a pre-partitioned disk and an existing Btrfs filesystem on the selected root partition, then inspect the installer output around the failing mkfs command. Done means the selected partition can be installed to successfully, or the installer clearly offers a force or wipe option before mkfs runs.

Written by the indexing model from the issue text.