Update python2 dependencies to python3 and clean deprecated requirements

QubesOS/qubes-issues#5289
QubesOS/qubes-issues#5297

misc/qvm-features-request

@@ -1,4 +1,4 @@
-#!/usr/bin/python2
+#!/usr/bin/python3
 # vim: fileencoding=utf-8
 
 #

rpm_spec/core-agent.spec.in

@@ -127,9 +127,9 @@ Requires:   pygobject3-base
 Requires:   dbus-python
 # for qubes-session-autostart, xdg-icon
 Requires:   pyxdg
-Requires:   python-daemon
+Requires:   python3-daemon
 # for qvm-feature-request
-Requires:   python2-qubesdb
+Requires:   python3-qubesdb
 Requires:   ImageMagick
 Requires:   librsvg2-tools
 Requires:   zenity
@@ -137,11 +137,7 @@ Requires:   dconf
 Requires:   qubes-core-qrexec-vm
 Requires:   qubes-libvchan
 Requires:   qubes-db-vm
-%if 0%{?fedora} >= 23
 Requires:   python%{python3_pkgversion}-dnf-plugins-qubes-hooks
-%else
-Requires:   python2-dnf-plugins-qubes-hooks
-%endif
 Obsoletes:  qubes-core-vm-kernel-placeholder <= 1.0
 Obsoletes:  qubes-upgrade-vm < 3.2
 Provides:   qubes-core-vm = %{version}-%{release}
@@ -156,8 +152,10 @@ BuildRequires: libX11-devel
 BuildRequires: qubes-utils-devel >= 3.1.3
 BuildRequires: qubes-libvchan-@BACKEND_VMM@-devel
 BuildRequires: pam-devel
-%if 0%{?rhel} >= 7
+%if 0%{?rhel} == 7
 BuildRequires: python-setuptools
+%else
+BuildRequires: python%{python3_pkgversion}-setuptools
 %endif
 BuildRequires: systemd
 Source0: %{name}-%{version}.tar.gz