Incorrect Opensearch version for 2.4.7-p7, 2.4.6-p12, 2.4.5-p14 and 2.4.4-p15

[rhubinak]

Issue in ./help/installation/system-requirements.md

You need to use OpenSearch: 2, not 2.19

[meker12]

Documentation has been updated -- see https://experienceleague.adobe.com/en/docs/commerce-operations/installation-guide/system-requirements