Update EOL date

[dhmlau]

There are a number of repos that mark "Apr 2023 minimum" as the EOL date. Since this date has passed, it might create confusion to users. It should be updated to "2026-04-30 minimum" to go with Node.js 20 EOL date.

Repos that need to be changed/checked:

• loopback-datasource-juggler docs: update EOL date loopback-datasource-juggler#2180
• loopback-connector-postgresql docs: update LTS dates loopback-connector-postgresql#643