perf(chstorage): compute column list only once

```
cpu: AMD Ryzen 9 5950X 16-Core Processor
                │   old.txt   │               new.txt               │
                │   sec/op    │   sec/op     vs base                │
InserterLogs-32   16.30m ± 1%   14.32m ± 1%  -12.16% (p=0.000 n=15)

                │   old.txt    │               new.txt                │
                │     B/op     │     B/op      vs base                │
InserterLogs-32   7.333Mi ± 0%   4.301Mi ± 0%  -41.34% (p=0.000 n=15)

                │   old.txt   │              new.txt               │
                │  allocs/op  │  allocs/op   vs base               │
InserterLogs-32   78.96k ± 0%   73.94k ± 0%  -6.36% (p=0.000 n=15)
```

internal/chstorage/columns_logs.go

@@ -1,6 +1,8 @@
 package chstorage
 
 import (
+	"sync"
+
 	"github.com/ClickHouse/ch-go/proto"
 	"go.opentelemetry.io/collector/pdata/pcommon"
 	"go.opentelemetry.io/collector/pdata/plog"
@@ -38,10 +40,12 @@ type logColumns struct {
 	scopeName       *proto.ColLowCardinality[string]
 	scopeVersion    *proto.ColLowCardinality[string]
 	scopeAttributes *Attributes
+
+	columns func() Columns
 }
 
 func newLogColumns() *logColumns {
-	return &logColumns{
+	c := &logColumns{
 		serviceName:       new(proto.ColStr).LowCardinality(),
 		serviceInstanceID: new(proto.ColStr).LowCardinality(),
 		serviceNamespace:  new(proto.ColStr).LowCardinality(),
@@ -53,6 +57,32 @@ func newLogColumns() *logColumns {
 		scopeVersion:      new(proto.ColStr).LowCardinality(),
 		scopeAttributes:   NewAttributes(colScope),
 	}
+	c.columns = sync.OnceValue(func() Columns {
+		return MergeColumns(Columns{
+			{Name: "service_instance_id", Data: c.serviceInstanceID},
+			{Name: "service_name", Data: c.serviceName},
+			{Name: "service_namespace", Data: c.serviceNamespace},
+
+			{Name: "timestamp", Data: c.timestamp},
+
+			{Name: "severity_number", Data: &c.severityNumber},
+			{Name: "severity_text", Data: c.severityText},
+
+			{Name: "trace_id", Data: &c.traceID},
+			{Name: "span_id", Data: &c.spanID},
+			{Name: "trace_flags", Data: &c.traceFlags},
+
+			{Name: "body", Data: &c.body},
+
+			{Name: "scope_name", Data: c.scopeName},
+			{Name: "scope_version", Data: c.scopeVersion},
+		},
+			c.attributes.Columns(),
+			c.scopeAttributes.Columns(),
+			c.resource.Columns(),
+		)
+	})
+	return c
 }
 
 func (c *logColumns) StaticColumns() []string {
@@ -153,32 +183,6 @@ func (c *logColumns) AddRow(r logstorage.Record) {
 	c.scopeAttributes.Append(r.ScopeAttrs)
 }
 
-func (c *logColumns) columns() Columns {
-	return MergeColumns(Columns{
-		{Name: "service_instance_id", Data: c.serviceInstanceID},
-		{Name: "service_name", Data: c.serviceName},
-		{Name: "service_namespace", Data: c.serviceNamespace},
-
-		{Name: "timestamp", Data: c.timestamp},
-
-		{Name: "severity_number", Data: &c.severityNumber},
-		{Name: "severity_text", Data: c.severityText},
-
-		{Name: "trace_id", Data: &c.traceID},
-		{Name: "span_id", Data: &c.spanID},
-		{Name: "trace_flags", Data: &c.traceFlags},
-
-		{Name: "body", Data: &c.body},
-
-		{Name: "scope_name", Data: c.scopeName},
-		{Name: "scope_version", Data: c.scopeVersion},
-	},
-		c.attributes.Columns(),
-		c.scopeAttributes.Columns(),
-		c.resource.Columns(),
-	)
-}
-
 func (c *logColumns) Input() proto.Input                { return c.columns().Input() }
 func (c *logColumns) Result() proto.Results             { return c.columns().Result() }
 func (c *logColumns) ChsqlResult() []chsql.ResultColumn { return c.columns().ChsqlResult() }
@@ -187,17 +191,19 @@ func (c *logColumns) Reset()                            { c.columns().Reset() }
 type logAttrMapColumns struct {
 	name proto.ColStr // http_method
 	key  proto.ColStr // http.method
-}
 
-func newLogAttrMapColumns() *logAttrMapColumns {
-	return &logAttrMapColumns{}
+	columns func() Columns
 }
 
-func (c *logAttrMapColumns) columns() Columns {
-	return []Column{
-		{Name: "name", Data: &c.name},
-		{Name: "key", Data: &c.key},
-	}
+func newLogAttrMapColumns() *logAttrMapColumns {
+	c := &logAttrMapColumns{}
+	c.columns = sync.OnceValue(func() Columns {
+		return []Column{
+			{Name: "name", Data: &c.name},
+			{Name: "key", Data: &c.key},
+		}
+	})
+	return c
 }
 
 func (c *logAttrMapColumns) Input() proto.Input                { return c.columns().Input() }