fix: allow disabling projections for specific instances (#10421)

# Which Problems Are Solved

The current handling of event subscriptions for actions is bad, esp. on
instances with a lot of events
(https://github.com/zitadel/zitadel/issues/9832#issuecomment-2866236414).
This led to severe problems on zitadel.cloud for such instances.

# How the Problems Are Solved

As a workaround until the handling can be improved, we introduce an
option for projections to be disabled completely for specific instances:
`SkipInstanceIDs`

# Additional Changes

None

# Additional Context

- relates to https://github.com/zitadel/zitadel/issues/9832

internal/query/projection/config.go

@@ -26,4 +26,5 @@ type CustomConfig struct {
 	ConcurrentInstances *uint
 	BulkLimit           *uint16
 	TransactionDuration *time.Duration
+	SkipInstanceIDs     []string
 }

internal/query/projection/projection.go

@@ -275,6 +275,7 @@ func applyCustomConfig(config handler.Config, customConfig CustomConfig) handler
 	if customConfig.TransactionDuration != nil {
 		config.TransactionDuration = *customConfig.TransactionDuration
 	}
+	config.SkipInstanceIDs = append(config.SkipInstanceIDs, customConfig.SkipInstanceIDs...)
 
 	return config
 }