[v14] Web: Add new supported aws region (il-central-1) to selector

[kimlisa]

Backport #31825 to branch/v14

[zmb3]

I thought discovery still doesn't support this region in older branches? @greedy52

[marcoandredinis]

I thought discovery still doesn't support this region in older branches? @greedy52

This is not used by the discovery_service
It will only fetch a single database information and add it as a Database to teleport (the same as adding the info to the db_service or using a tctl create <database>.yaml)

[marcoandredinis]

@kimlisa Sorry for removing the auto-merge, let's clarify Zac's question first

[greedy52]

I thought discovery still doesn't support this region in older branches? @greedy52

AWS SDK in general works with "unknown" regions so this should be fine.

(For context), an error was thrown if an unknown region was found when parsing the discovery service's static config. I've changed this behaviour to do a regex validation instead of testing against a list of known regions. That change will be backported today as well.