Add OPENSEARCH_URL

[htuscher]

1. Why is this change necessary?

Since Shopware 6.5 the environment variable to configure the Opensearch URL is no longer called SHOPWARE_ES_HOSTS but is now OPENSEARCH_URL.

2. What does this change do, exactly?

It also sets the env variable OPENSEARCH_URL according to the option cfg.elasticsearchPort so switching the default port would also work with Shopware 6.5

4. Please link to the relevant issues (if any).

https://developer.shopware.com/docs/guides/hosting/infrastructure/elasticsearch/elasticsearch-setup.html#variables-in-your-env

5. Checklist

• I have rebased my changes to remove merge conflicts
• I have written or adjusted the documentation according to my changes

[lx-wnk]

Thank you for your contribution! 🎉
Your change will be included in the upcoming release.