Update Build-Deps for Trixie

Switch from deprecated pkg-config to pkgconf.
Switch from systemd to systemd-dev which contains now pkg-config files.

Signed-off-by: Dylan Aïssi <dylan.aissi@collabora.com>

debian/control

@@ -7,8 +7,8 @@ Build-Depends: debhelper (>= 10),
                libjson-glib-dev,
                libsoup2.4-dev,
                meson,
-               pkg-config,
-               systemd,
+               pkgconf,
+               systemd-dev,
                libsystemd-dev
 Standards-Version: 4.4.1