Update layout names for South beta layouts in production model 7.0.0.

[GernotMaier]

(a bit cumbersome)

[Copilot]

Pull request overview

Updates integration test workflow configs to use version-dependent array layout names, aligning South “alpha/beta” layouts with the renamed CTAO layout identifiers introduced for production model 7.0.0.

Changes:

• Switched several simtools-simulate-prod integration test configs from a single array_layout_name string to a by_version mapping (<7.0.0 vs >=7.0.0).
• Updated expected output filenames in the “multiple model versions” South gamma config (currently inconsistent with the model versions under test).
• Added a changelog fragment documenting the layout-name update.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
tests/integration_tests/config/simulate_prod_gamma_62_deg_south_check_output.yml	Use array_layout_name.by_version to map beta → CTAO-South-Beta for model_version >= 7.0.0.
tests/integration_tests/config/simulate_prod_gamma_40_deg_south_corsika_only.yml	Same by_version mapping for the South beta layout.
tests/integration_tests/config/simulate_prod_gamma_40_deg_south_check_output.yml	Same by_version mapping for the South beta layout.
tests/integration_tests/config/simulate_prod_gamma_20_deg_south_multiple_model_versions.yml	Introduce by_version mapping for South alpha layout, but expected output filenames were changed inconsistently for 6.x model versions.
docs/changes/2164.model.md	Changelog fragment for the layout-name update.