Add missing endregion marker in samples #1265

Job	Run time
test / EventStore.Client.Streams/ubuntu-latest/net6.0/ci	11m 38s
test / EventStore.Client.PersistentSubscriptions/ubuntu-latest/net6.0/ci	9m 27s
test / EventStore.Client.Operations/ubuntu-latest/net6.0/ci	2m 43s
test / EventStore.Client.UserManagement/ubuntu-latest/net6.0/ci	2m 14s
test / EventStore.Client.ProjectionManagement/ubuntu-latest/net6.0/ci	1m 43s
test / EventStore.Client.Streams/ubuntu-latest/net7.0/ci	10m 30s
test / EventStore.Client.PersistentSubscriptions/ubuntu-latest/net7.0/ci	9m 29s
test / EventStore.Client.Operations/ubuntu-latest/net7.0/ci	2m 23s
test / EventStore.Client.UserManagement/ubuntu-latest/net7.0/ci	2m 22s
test / EventStore.Client.ProjectionManagement/ubuntu-latest/net7.0/ci	1m 39s
test / EventStore.Client.Streams/ubuntu-latest/net8.0/ci	11m 3s
test / EventStore.Client.PersistentSubscriptions/ubuntu-latest/net8.0/ci	9m 21s
test / EventStore.Client.Operations/ubuntu-latest/net8.0/ci	2m 12s
test / EventStore.Client.UserManagement/ubuntu-latest/net8.0/ci	2m 46s
test / EventStore.Client.ProjectionManagement/ubuntu-latest/net8.0/ci	1m 26s
	1h 20m 56s

Provide feedback