github: simplify release-to-pypi action

We can just let pipx install poetry for us and we don't need a special
Python install or to run `poetry install`.

Also update action versions while we are touching this.

.github/workflows/release-to-pypi.yml

@@ -6,17 +6,10 @@ on:
 
 jobs:
   build_and_publish:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
     steps:
-    - uses: actions/checkout@v2
-    - uses: actions/setup-python@v2
-      with:
-        python-version: 3.8
-    - uses: abatilo/[email protected]
-      with:
-        poetry-version: 1.1.6
-    - run: poetry install
-    - run: poetry build
-    - run: poetry publish
+    - uses: actions/checkout@v3
+    - run: pipx run poetry build
+    - run: pipx run poetry publish
       env:
         POETRY_PYPI_TOKEN_PYPI: ${{ secrets.PYPI_TOKEN }}