perf(chstorage): do not make an unnecessary copy of encoded attributes

```
                │   old.txt    │              new.txt               │
                 │    sec/op    │   sec/op     vs base               │
_metricsBatch-32   1088.5µ ± 1%   992.1µ ± 1%  -8.86% (p=0.000 n=15)

                 │   old.txt    │               new.txt                │
                 │     B/op     │     B/op      vs base                │
_metricsBatch-32   290.8Ki ± 0%   156.4Ki ± 0%  -46.23% (p=0.000 n=15)

                 │   old.txt   │               new.txt               │
                 │  allocs/op  │  allocs/op   vs base                │
_metricsBatch-32   6.280k ± 0%   3.247k ± 0%  -48.30% (p=0.000 n=15)
```

internal/chstorage/attributes.go

@@ -5,6 +5,7 @@ import (
 
 	"github.com/ClickHouse/ch-go/proto"
 	"github.com/go-faster/errors"
+	"github.com/go-faster/jx"
 	"go.opentelemetry.io/collector/pdata/pcommon"
 	"golang.org/x/exp/maps"
 
@@ -68,7 +69,13 @@ func (a *attributeCol) Append(v otelstorage.Attrs) {
 	if !ok {
 		idx = len(a.hashes)
 		a.hashes[h] = idx
-		a.index.Append(encodeAttributes(v.AsMap()))
+
+		e := jx.GetEncoder()
+		defer jx.PutEncoder(e)
+		encodeMap(e, v.AsMap())
+
+		// Append will copy passed bytes.
+		a.index.Append(e.Bytes())
 	}
 	a.col.AppendKey(idx)
 }