Fix goroutine leak in hooks execution group

[linux019]

This function creates an unbuffered channel

prebid-server/hooks/hookexecution/execution.go

Line 70 in ec6a45d

resp := make(chan hookResponse[P])

If hook returns Reject error the collectHookResponses aborts reading of the channel

prebid-server/hooks/hookexecution/execution.go

Line 138 in ec6a45d

break

and this results to dead goroutine in

prebid-server/hooks/hookexecution/execution.go

Line 76 in ec6a45d

go func(hw hooks.HookWrapper[H], moduleCtx hookstage.ModuleInvocationContext) {

because the channel is still open and goroutines can still write to this channel. As this channel is no more read by anyone the writing goroutine will stuck indefinitely awaiting release of the channel

#3754

[linux019]

@bsardo Please review