[pyproject] Added fallback_version to setuptools_scm.

Should allow

pip install https://gitlab.opengeosys.org/ogs/tools/ogstools/-/archive/main/ogstools-main.zip

https://setuptools-scm.readthedocs.io/en/latest/config/#configuration-parameters

pyproject.toml

@@ -37,7 +37,8 @@ include = ["ogstools*"]
 namespaces = false
 
 [tool.setuptools_scm]
-version_scheme = "no-guess-dev" # would increment version otherwise
+version_scheme = "no-guess-dev"         # would increment version otherwise
+fallback_version = "0.1.0.post0+no-scm" # Manually increment on release!
 
 [project.scripts]
 msh2vtu = 'ogstools.msh2vtu._cli:cli'