New comment by xtraeme on void-packages repository

https://github.com/void-linux/void-packages/issues/20577#issuecomment-607948700

Comment:
Just to be safe, the script should do:

```
for f in ${archs}; do
    XBPS_ARCH=$f xbps-rindex -a repo/*.xbps
done

for f in ${archs}; do
    export XBPS_ARCH=$f
    xbps-rindex -c repo
    xbps-rindex -r repo
done
```