spanconfigreconcilerccl: deflake spanconfigreconcilerccl_test

Previously, the span config reconciller tests when running under a
tenant did not use the transactional descriptor ID generator, which
could lead to flake. Additionally, the transactional ID generator also was
not being used for creating internal objects, when the testing knob is
enabled. This patch fixes the multi-tenant tests to use the
transactional ID generator and enables it for internal queries as well.

Fixes: #154585

Release note: None

Author: fqazi

pkg/spanconfig/spanconfigtestutils/spanconfigtestcluster/cluster.go

@@ -71,6 +71,9 @@ func (h *Handle) InitializeTenant(ctx context.Context, tenID roachpb.TenantID) *
 				SpanConfig:     h.scKnobs,
 				GCJob:          &tenantGCJobKnobs,
 				UpgradeManager: serverUpgradeKnobs,
+				SQLExecutor: &sql.ExecutorTestingKnobs{
+					UseTransactionalDescIDGenerator: true,
+				},
 			},
 		}
 		var err error

pkg/sql/planner.go

@@ -24,6 +24,7 @@ import (
 	"github.com/cockroachdb/cockroach/pkg/sql/catalog"
 	"github.com/cockroachdb/cockroach/pkg/sql/catalog/catsessiondata"
 	"github.com/cockroachdb/cockroach/pkg/sql/catalog/colinfo"
+	"github.com/cockroachdb/cockroach/pkg/sql/catalog/descidgen"
 	"github.com/cockroachdb/cockroach/pkg/sql/catalog/descpb"
 	"github.com/cockroachdb/cockroach/pkg/sql/catalog/descs"
 	"github.com/cockroachdb/cockroach/pkg/sql/catalog/lease"
@@ -462,6 +463,9 @@ func newInternalPlanner(
 	p.extendedEvalCtx.NodeID = execCfg.NodeInfo.NodeID
 	p.extendedEvalCtx.Locality = execCfg.Locality
 	p.extendedEvalCtx.DescIDGenerator = execCfg.DescIDGenerator
+	if execCfg.TestingKnobs.UseTransactionalDescIDGenerator && txn != nil {
+		p.extendedEvalCtx.DescIDGenerator = descidgen.NewTransactionalGenerator(execCfg.Settings, execCfg.Codec, txn)
+	}
 
 	p.sessionDataMutatorIterator = smi