Use upstream AppStream metadata

See https://www.freedesktop.org/software/appstream/docs/chap-Metadata.html#spec-component-location

quassel.spec

@@ -55,10 +55,6 @@ Source1: quasselcore.service
 Source2: quassel.conf
 Source3: quassel.sysusers
 
-# Appstream metadata, for GNOME Software.
-Source4: quassel.appdata.xml
-Source5: quasselclient.appdata.xml
-
 %description
 Quassel IRC is a modern, distributed IRC client,
 meaning that one (or multiple) client(s) can attach
@@ -123,10 +119,12 @@ install -Dp -m 0644 %{SOURCE3} %{buildroot}%{_sysusersdir}/%{name}.conf
 # Home directory for quassel user
 install -d -m 0750 %{buildroot}/%{quassel_data_dir}
 
-# Install the appdata files.
-mkdir %{buildroot}%{_datadir}/appdata/
-cp -a %{SOURCE4} %{SOURCE5} %{buildroot}%{_datadir}/appdata/
-appstream-util validate-relax --nonet %{buildroot}/%{_datadir}/appdata/*.appdata.xml
+# Install AppStream metadata
+install -d -m 0755 %{buildroot}%{_datadir}/metainfo
+install -p -m 0644 data/*.appdata.xml %{buildroot}%{_datadir}/metainfo/
+
+%check
+appstream-util validate-relax --nonet %{buildroot}/%{_datadir}/metainfo/*.appdata.xml
 
 # Core pre/post macros.
 %pre core
@@ -145,7 +143,7 @@ appstream-util validate-relax --nonet %{buildroot}/%{_datadir}/appdata/*.appdata
 %files
 %{_kf5_bindir}/quassel
 %{_kf5_datadir}/applications/quassel.desktop
-%{_datadir}/appdata/quassel.appdata.xml
+%{_datadir}/metainfo/quassel.appdata.xml
 
 %files common
 %doc README.md
@@ -172,6 +170,7 @@ appstream-util validate-relax --nonet %{buildroot}/%{_datadir}/appdata/*.appdata
 %changelog
 * Thu Feb 10 2022 Timothée Ravier <tim@siosm.fr> - 0.13.1-11
 - Use systemd sysusers config to create user and group
+- Use upstream AppStream metadata
 
 * Fri Jan 21 2022 Fedora Release Engineering <releng@fedoraproject.org> - 0.13.1-10
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_36_Mass_Rebuild