Currently install_deps.sh treats all other distributions (that aren't deb, arch or rpm based) as rpm distributions. And it doesn't detect OpenSUSE.
It treats all other distributions as rpm based because of a faulty check [ -f /etc/redhat-release -o /etc/SuSE-release ] (at line 5951) which always evaluates to true because of a missing -f before /etc/SuSE-release.
It also doesn't detect OpenSUSE because the detection sequence checks the existence of the file /etc/SuSE-release which was deprecated in OpenSUSE 13.1 and removed in OpenSUSE Leap 15.0 in favour of /etc/os-release. (os-release was already used in install_deps.sh but only to build packman repo's url). See https://en.opensuse.org/Etc_SuSE-release.
This patch fixes both issues and also modifies the code used to build packman repo's url to take into account both OpenSUSE Leap and Tumbleweed (the urls for the two distributions do not use the same format).
I tested the patch on OpenSUSE Leap 15.2, OpenSUSE Tumbleweed, Fedora 33 (to check for regressions) and Slackware 14.2. and it seems to work :)