ci: fix Linux build — install libgirepository-2.0-dev for PyGObject

PyGObject >= 3.52 dropped the standalone gobject-introspection
girepository-1.0 dependency and now builds against girepository-2.0,
which was merged into GLib 2.80. The linux extra pins PyGObject>=3.46
with no upper bound, so pip resolves the newest release (3.56.3) and
meson aborts metadata generation with:

  Dependency 'girepository-2.0' is required but not found.

because CI only installed the old libgirepository1.0-dev.

Swap libgirepository1.0-dev -> libgirepository-2.0-dev (shipped by
GLib 2.80 on the ubuntu-latest / 24.04 runner) across all three Linux
pip-install paths so they stay in sync:

- test.yml: the failing linux-smoke job.
- release.yml: build-linux, which would otherwise ship a broken
  Linux tarball on the next tag.
- build.yml: build-linux had no system-deps step at all; added the
  matching apt install so the manual artifact build works too.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.gitea/workflows/build.yml

@@ -60,6 +60,16 @@ jobs:
         with:
           python-version: '3.11'
 
+      - name: Install native deps for dbus-python + PyGObject
+        run: |
+          # PyGObject >= 3.52 builds against girepository-2.0 (merged into
+          # GLib 2.80), not the old standalone girepository-1.0. ubuntu-latest
+          # (24.04) ships it as libgirepository-2.0-dev.
+          sudo apt-get update
+          sudo apt-get install -y --no-install-recommends \
+            libdbus-1-dev libglib2.0-dev pkg-config \
+            libcairo2-dev libgirepository-2.0-dev
+
       - name: Build Linux distribution
         run: |
           chmod +x build-dist-linux.sh

.gitea/workflows/release.yml

@@ -193,10 +193,13 @@ jobs:
 
       - name: Install native deps for dbus-python + PyGObject
         run: |
+          # PyGObject >= 3.52 builds against girepository-2.0 (merged into
+          # GLib 2.80), not the old standalone girepository-1.0. ubuntu-latest
+          # (24.04) ships it as libgirepository-2.0-dev.
           sudo apt-get update
           sudo apt-get install -y --no-install-recommends \
             libdbus-1-dev libglib2.0-dev pkg-config \
-            libcairo2-dev libgirepository1.0-dev
+            libcairo2-dev libgirepository-2.0-dev
 
       - name: Build Linux distribution
         run: |

.gitea/workflows/test.yml

@@ -57,10 +57,13 @@ jobs:
 
       - name: Install Linux system deps for dbus-python + PyGObject
         run: |
+          # PyGObject >= 3.52 builds against girepository-2.0 (merged into
+          # GLib 2.80), not the old standalone girepository-1.0. ubuntu-latest
+          # (24.04) ships it as libgirepository-2.0-dev.
           sudo apt-get update
           sudo apt-get install -y --no-install-recommends \
             libdbus-1-dev libglib2.0-dev pkg-config \
-            libcairo2-dev libgirepository1.0-dev
+            libcairo2-dev libgirepository-2.0-dev
 
       - name: Install with linux extra
         run: |