workflows: add workflow for running tests

This uses the python:3.13 docker image and also installs uv
beforehand. Checkout is performed "manually" because the standard
actions/checkout@v4 action requires node:20 as container, which is
annoying. I don't want to pull in node just to clone a git repo.

Signed-off-by: Max R. Carrara <max@aequito.sh>

.forgejo/workflows/testing.yaml

@@ -0,0 +1,28 @@
+on: [push]
+
+env:
+  GIT_CLONE_PATH: "project"
+
+jobs:
+  test:
+    runs-on: docker
+    # Note: will require node:20 for running actions/checkout@v4 and actions/cache@v4
+    # So... should maybe build a custom image or something? Image registry?
+    container:
+      image: python:3.13
+    steps:
+      - name: Download & install uv
+        run: |
+          set -ex
+          curl -LsSf https://astral.sh/uv/install.sh | sh
+      - name: Clone repository
+        run: |
+          set -ex
+          FORGE_URL="$(echo ${{ github.server_url }}/${{ github.repository }}.git | sed 's#https://##')"
+          git clone --depth 1 "https://x-access-token:${{ secrets.GITHUB_TOKEN }}@${FORGE_URL}" "${GIT_CLONE_PATH}"
+      - name: Run tests
+        run: |
+          set -ex
+          . $HOME/.local/bin/env
+          cd project && uv run pytest
+