Port to libgirepository-2.0

pygobject 3.52 has switched [1] to using libgirepository-2.0 which
comes from glib itself now, rather than the 1.0 which came from
gobject-introspection.

This means that it fails to load the incompatible "GIRepository 2.0"
and thus must be ported to 3.0 (which is provided by
libgirepository-2.0).

This also means that we have to bump the minimum version of glib to
2.80

Migration guide is here [2]

[1]: https://gitlab.gnome.org/GNOME/pygobject/-/merge_requests/320
[2]: https://docs.gtk.org/girepository/migrating-gi.html

blueprintcompiler/gir.py

@@ -24,7 +24,7 @@ from functools import cached_property
 
 import gi  # type: ignore
 
-gi.require_version("GIRepository", "2.0")
+gi.require_version("GIRepository", "3.0")
 from gi.repository import GIRepository  # type: ignore
 
 from . import typelib, xml_reader
@@ -42,7 +42,8 @@ def add_typelib_search_path(path: str):
 
 
 def get_namespace(namespace: str, version: str) -> "Namespace":
-    search_paths = [*GIRepository.Repository.get_search_path(), *_user_search_paths]
+    repo = GIRepository.Repository()
+    search_paths = [*repo.get_search_path(), *_user_search_paths]
 
     filename = f"{namespace}-{version}.typelib"
 
@@ -73,8 +74,9 @@ def get_available_namespaces() -> T.List[T.Tuple[str, str]]:
     if len(_available_namespaces):
         return _available_namespaces
 
+    repo = GIRepository.Repository()
     search_paths: list[str] = [
-        *GIRepository.Repository.get_search_path(),
+        *repo.get_search_path(),
         *_user_search_paths,
     ]
 

meson.build

@@ -7,6 +7,9 @@ datadir = join_paths(prefix, get_option('datadir'))
 
 py = import('python').find_installation('python3')
 
+dependency('glib-2.0', version: '>= 2.80.0')
+dependency('girepository-2.0', version: '>= 2.80.0')
+
 subdir('docs')
 
 configure_file(