Allow matrix build without Exasol Version

[redcatbear]

Summary

If SaaS is used as backend for the integration test instead of the ITDE, users should not provide a list of Exasol versions to generate the integration test matrix.

Currently, an empty list of Exasol versions results in a matrix that has zero values in one dimension and thus is not executed.

Workaround

As a workaround, users can add a bogus version number.

Details

The following should be valid code in the noxconfig.py:

PROJECT_CONFIG = Config(
    # ...
    python_versions=("3.10", "3.11", "3.12", "3.13"),
    # Uses SaaS; not ITDE DB versions
    exasol_versions=(),
)

Task(s)

• Add feature "empty Exasol version in matrix definition"
• Bump version number (minor)
• Update documentation
• Update changelog