appease mypy Version no-untyped-call (#864)

* appease mypy Version no-untyped-call

Without the type hint we get:
error: Call to untyped function "Version" in typed
context  [no-untyped-call]

Note that our Version is derived from semantic_version, which
doesn't have type hints.

* mark class definition __init__ functions -> None.

This prevents reviewdog from generating an no-untyped-call warning
when a new instance of the class is created.  This behavior is
a time bomb.  reviewdog flags the warning at the line the new instance
was added, which is within the scope of the diffs, but the problem lies
elsewhere, in the class definition.

* fix mypy import-untyped error.

pyproject.toml

@@ -69,6 +69,7 @@ check = [
     "pygments",
     "packaging",
     "pylint",
+    "types-requests",
 ]
 docs = [
     "sphinx>=7.0",