ci: publish on test pypi

.github/workflows/publish-testpypi.yaml

@@ -0,0 +1,41 @@
+name: Publish package on Test PyPI
+
+on:
+  push:
+    tags:
+      - '*.*.*'
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      # check-out repo and set-up python
+      - name: Check out repository
+        uses: actions/checkout@v4
+      - name: Set up python
+        id: setup-python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.9"
+
+      # install & configure poetry
+      - name: Install Poetry
+        uses: snok/install-poetry@v1
+        with:
+          virtualenvs-create: true
+          virtualenvs-in-project: true
+          installer-parallel: true
+
+      # configure credentials
+      - name: Configure credentials
+        run: |
+          poetry config repositories.testpypi https://test.pypi.org/legacy/
+          poetry config pypi-token.testpypi ${{ secrets.TEST_PYPI_API_KEY }}
+
+      # build package
+      - name: Build package
+        run: poetry build
+
+      # publish package
+      - name: Publish package
+        run: poetry publish --repository testpypi