Remove ignored entries from pyproject.toml's for exasol-provided packages

[ArBridgeman]

Summary

In the packages contained in this repo, we have pyproject.toml's defined with entries like:

[[tool.mypy.overrides]]
module = [
    "test.unit.*",
    "test.integration.*",
    "exasol.pytest_backend.*",
    "pyexasol.*",
]

This tells mypy to ignore such imports in the checks, and it typically arises as the packages are missing a py.typed file.

By adding py.typed files to these packages, we should be able to remove these entries from the ignore list.

Tasks

• Check that the used release of these packages has a py.typed file:
  • exasol.pytest_backend.* -> possible since 0.4.0 #96: Updated dependencies #97
  • exasol.saas.* -> possible since 2.2.0 Security/relock dependencies for requests urllib3 #102 (only bumped ones tested in CI)
  • pyexasol.* -> todo in ✨ Add typing support to pyexasol pyexasol#162
• Update the 5 pyproject.toml files
• Verify locally that poetry run -- nox -s lint:typing succeeds, as expected, for each