[Platform] Update model list - delete old entries

[lochmueller]

Hey everone,

I found out, that the model list of OpenRouter contains many models, that do not exist anymore. The reason is, that the automatic update process "merge" the model list and do not drop old one (also for the other Bridges).

https://github.com/symfony/ai/blob/main/src/platform/dev/update-model-catalogs.php#L166
https://github.com/symfony/ai/blob/main/src/platform/dev/update-model-catalogs.php#L171

There is a "merge" parameter that is true.

Question:

• Is there a reason why we keep the old models, that do not exists anymore? I prefere a PR that remote the "merge" flag and always sync the list.
• After that I would drop this script https://github.com/symfony/ai/blob/main/src/platform/src/Bridge/OpenRouter/updateStaticModelCatalog becaus with "merge = false" the output of the central update is the same.

What are your thoughts? Should I prepare a PR....