ci: use total commit count for unique TestPyPI dev version

Also updated Python README.md to show how to install from TestPyPI

Signed-off-by: Martin Belanger <[email protected]>

Author: Martin Belanger

.github/workflows/libnvme-release-python.yml

@@ -66,7 +66,7 @@ jobs:
         id: version
         run: |
           TAG=$(git describe --tags --abbrev=0)
-          REV=$(git rev-list "$TAG"..HEAD --count)
+          REV=$(git rev-list HEAD --count)
           BASE_VERSION="${TAG#v}"
           VERSION="${BASE_VERSION}.dev${REV}"
           echo "dev_version=$VERSION" >> $GITHUB_OUTPUT

libnvme/libnvme/README.md

@@ -64,3 +64,13 @@ host = None
 ctx = None
 ```
 
+## Testing PyPI package
+
+Use the following command to test installing the package from TestPyPI before publishing to the official PyPI registry.
+
+```bash
+pip install \
+  --index-url https://test.pypi.org/simple/ \
+  --extra-index-url https://pypi.org/simple/ \
+  libnvme==[libnvme-version]
+```