Avoid reallocating map in MatchLabels (#10715)

We know the max size of our map so we can create it with that information and avoid extra allocations

Signed-off-by: Łukasz Mierzwa <l.mierzwa@gmail.com>

model/labels/labels.go

@@ -119,7 +119,7 @@ func (ls *Labels) UnmarshalYAML(unmarshal func(interface{}) error) error {
 func (ls Labels) MatchLabels(on bool, names ...string) Labels {
 	matchedLabels := Labels{}
 
-	nameSet := map[string]struct{}{}
+	nameSet := make(map[string]struct{}, len(names))
 	for _, n := range names {
 		nameSet[n] = struct{}{}
 	}