rootless podman, permission issues

Hi,

running dabuild with podman (rootless) results in permission denied issues as the mounted aports tree is mapped to the root user:

[john:~/workspace/aports/testing/signal-cli] dabuild checksum
[...]
sed: can't create temp file '/home/builder/aports/testing/signal-cli/APKBUILDXXXXXX': Permission denied

Setting the correct uidmap / gidmap arguments makes it work again:

[john:~/workspace/aports/testing/signal-cli] cat /etc/dabuild.conf 
#!/bin/sh
DABUILD_DOCKER=podman
DABUILD_ARGS="--uidmap 1000:0:1 --uidmap 0:1:1000 --gidmap 1000:0:1 --gidmap 0:1:1000"

[john:~/workspace/aports/testing/signal-cli] id
uid=1000(john) gid=1000(john) groups=1000(john),4(adm),24(cdrom),27(sudo),30(dip),46(plugdev),100(users),116(docker),119(lpadmin),131(sambashare),138(libvirt)

Last, but not least, configuration should also be possible for an unprivileged user without access to /etc/ ,e.g by loading $HOME/.config/dabuild.conf after the system configuration.

Thanks!