fix(kds): remove context from map on stream close (backport of #12243) (

#12263)

## Motivation

Backport #12243

I had to do a manual backport because GitHub changed my merge method to
merge commit and this one cannot be backported.

## Implementation information

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and discarded -->

## Supporting documentation

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Fix #XX

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Signed-off-by: Lukasz Dziedziak <[email protected]>

pkg/kds/v2/server/tenant_callback.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"sync"
 
+	envoy_core "github.com/envoyproxy/go-control-plane/envoy/config/core/v3"
 	envoy_sd "github.com/envoyproxy/go-control-plane/envoy/service/discovery/v3"
 	envoy_xds "github.com/envoyproxy/go-control-plane/pkg/server/v3"
 
@@ -50,3 +51,9 @@ func (c *tenancyCallbacks) OnStreamDeltaRequest(streamID int64, request *envoy_s
 	util.FillTenantMetadata(tenantID, request.Node)
 	return nil
 }
+
+func (c *tenancyCallbacks) OnDeltaStreamClosed(streamID int64, _ *envoy_core.Node) {
+	c.Lock()
+	delete(c.streamToCtx, streamID)
+	c.Unlock()
+}