pyproject: use .dev{distance}, not +{node}, for non-release builds.

At the moment this uses a git URL for pdm-backend because required PDM
functionality (pdm-project/pdm-backend#217) is not released yet.

.github/workflows/main.yaml

@@ -132,6 +132,8 @@ jobs:
     steps:
       - name: Check out source code
         uses: actions/checkout@v4
+        with:
+            fetch-depth: 0
       - name: Set up PDM
         uses: pdm-project/setup-pdm@v4
         with:
@@ -260,4 +262,4 @@ jobs:
         GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
       with:
         tag_name: ${{ github.ref_name }}
-        release_name: ${{ steps.metadata.outputs.name }}
+        release_name: ${{ steps.metadata.outputs.name }}