full support of pep517

Since llast upgrade build is broken. Lets fully migrate to
pyproject.toml. Note for maintaners: because data_files option is
deprectated (see https://github.com/pypa/setuptools/discussions/2648)
you will have to install files manually inside your packaging process

docs/ahriman.rst

@@ -12,17 +12,6 @@ Subpackages
    ahriman.models
    ahriman.web
 
-Submodules
-----------
-
-ahriman.version module
-----------------------
-
-.. automodule:: ahriman.version
-   :members:
-   :no-undoc-members:
-   :show-inheritance:
-
 Module contents
 ---------------