fix poetry install in ubuntu 24.04

.gitea/actions/poetrybuild/action.yaml

@@ -12,8 +12,10 @@ inputs:
 runs:
   using: "composite"
   steps:
+    - name: Add pipx to PATH
+      run: echo "/root/.local/bin" >> ${GITHUB_PATH}
     - name: Install poetry
-      run: pip install poetry
+      run: pipx install poetry
     - name: Install poetry package
       run: poetry install --no-interaction ${{ inputs.poetry_install_args }}
       shell: bash

.gitea/workflows/selftests.yaml

@@ -14,11 +14,13 @@ on:
 jobs:
   # Test building the package and installing it via pip3
   test-build-install:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     steps:
       - uses: actions/checkout@v4
+      - name: Add pipx to PATH
+        run: echo "/root/.local/bin" >> ${GITHUB_PATH}
       - name: Install poetry
-        run: pip install poetry
+        run: pipx install poetry
       - name: Build package
         run: poetry build
       - name: Install package