Use Fedora since latest libadwaita needed for Gaphor

.github/constraints.txt

@@ -0,0 +1 @@
+poetry==1.7.1

.github/workflows/build.yml

@@ -6,8 +6,7 @@ on:
     types: [created, published]
 
 env:
-  PYTHON_VERSION: '3.11'
-  POETRY_VERSION: '1.4.1'
+  python_version: '3.12'
 
 permissions:
   contents: read
@@ -16,6 +15,8 @@ jobs:
 
   test:
     runs-on: ubuntu-22.04
+    container: fedora:39
+    timeout-minutes: 30
     permissions:
       contents: write
     steps:
@@ -27,18 +28,16 @@ jobs:
       - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
       - name: Install Linux Dependencies
         run: >
-          sudo apt-get update -qq && sudo apt-get install -qq --no-install-recommends
-          gir1.2-gtk-4.0 libgirepository1.0-dev libgtksourceview-5-dev libadwaita-1-dev
-          graphviz
-      - name: Set up Python ${{ env.PYTHON_VERSION }}
+          dnf install -y gcc git graphviz pkg-config python-launcher upx
+          xorg-x11-server-Xvfb gtk4 gobject-introspection-devel
+          cairo-gobject-devel gtksourceview5-devel libadwaita-devel cairo-devel
+          python${{ env.python_version }}-devel
+      - name: Set up Python ${{ env.python_version }}
         uses: actions/setup-python@0a5c61591373683505ea898e09a3ea4f39ef2b9c # v5.0.0
         with:
-          python-version: ${{ env.PYTHON_VERSION }}
-      - name: Install Poetry ${{ env.POETRY_VERSION }}
-        run: |
-          python -m pip install --upgrade pip
-          pip install poetry==$POETRY_VERSION
-          poetry config virtualenvs.in-project true
+          python-version: ${{ env.python_version }}
+      - name: Install Poetry
+        run: pipx install --python ${{ env.python_version }} --pip-args=--constraint=.github/constraints.txt poetry
       - name: Install dependencies
         run: poetry install --no-interaction
       - name: Gaphor self-test