Adapt to upstream packaging changes (#201)

 pkg-config: Added to Build-Depends
cython3-legacy: Added to Build-Depends for alternate

grpc can't build with cython-3_3.0.x on noble (Ubuntu 24.04) base. 
https://launchpadlibrarian.net/707999329/buildlog_ubuntu-noble-amd64.warpinator_1.8.3klbknoble1_BUILDING.txt.gz

cython3-legacy_0.29.x can be use instead.
https://launchpadlibrarian.net/708361123/buildlog_ubuntu-noble-amd64.warpinator_1.8.3klbknoble2_BUILDING.txt.gz

libpolkit-gobject-1-dev: Added to Build-Depends
libpolkit-gobject-1-dev package is required for mantic base and later.
https://launchpadlibrarian.net/707176618/buildlog_ubuntu-mantic-amd64.warpinator_1.8.2+klbkmantic2_BUILDING.txt.gz
https://launchpadlibrarian.net/707243769/buildlog_ubuntu-mantic-amd64.warpinator_1.8.2+klbkmantic3_BUILDING.txt.gz

debian/control

@@ -4,10 +4,12 @@ Priority: optional
 Maintainer: Linux Mint <[email protected]>
 Build-Depends:
  debhelper-compat (= 12),
- cython3,
+ cython3-legacy | cython3,
  curl,
  dh-python,
+ libpolkit-gobject-1-dev,
  meson (>= 0.45.0),
+ pkg-config,
  policykit-1,
  python3-dev,
  python3-setuptools,