Replace SquashFS with EROFS

[timocapa]

unRAID currently ships `bzmodules` and `bzfirmware` as SquashFS, however another read-only filesystem exists called EROFS, which should only be slightly bigger in image size than SquashFS, however it should be much faster, potentially translating to faster boot times. Everyone should gain from this, so I think it might be worth looking into.

 

References:

https://www.kernel.org/doc/html/v5.8/filesystems/erofs.html

https://www.usenix.org/system/files/atc19-gao.pdf

https://blog.sigma-star.at/post/2022/07/squashfs-erofs/

 

Command example: `mkfs.erofs -zlzma -C 65536 -Eztailpacking *image* *folder*`

 

Changes needed (as far as I can tell):

- Enable EROFS support in the kernel (with lzma support, as per example above, if wanted)

- Edit fstab to use `erofs` instead `squashfs` with only `ro` as mount option

[ich777]

@timocapa I will look into this, compare boot times and report back.

For newer Unraid beta versions everything is working a bit differently and this shouldn't matter much but I will try this.