[🍒5.10] utils: enable curl websockets support when building with `build.ps1`

[lxbndr]

trafficstars

Cherry-pick of #73378

[lxbndr]

cc @compnerd

[compnerd]

@swift-ci please test

[compnerd]

CC: @shahmishal @DougGregor @airspeedswift

[compnerd]

Explanation: Enable the WebSocket backend in CURL for allowing use of WebSockets through Foundation. Scope: This enables WebSocket support in CURL which is required for Foundation's WebSocket support to be enabled. Issue: Risk: Very low - either curl builds with the websocket support or fails to build in CI Testing: CI run Reviewer: @compnerd