refactor: use x/exp/slices instead of custom contains function

taskfile/included_taskfile.go

@@ -7,6 +7,7 @@ import (
 
 	"github.com/go-task/task/v3/internal/execext"
 	"github.com/go-task/task/v3/internal/filepathext"
+	"golang.org/x/exp/slices"
 
 	"gopkg.in/yaml.v3"
 )
@@ -72,7 +73,7 @@ func (tfs *IncludedTaskfiles) Set(key string, includedTaskfile IncludedTaskfile)
 	if tfs.Mapping == nil {
 		tfs.Mapping = make(map[string]IncludedTaskfile, 1)
 	}
-	if !stringSliceContains(tfs.Keys, key) {
+	if !slices.Contains(tfs.Keys, key) {
 		tfs.Keys = append(tfs.Keys, key)
 	}
 	tfs.Mapping[key] = includedTaskfile

taskfile/slice.go

@@ -1,10 +0,0 @@
-package taskfile
-
-func stringSliceContains(s []string, str string) bool {
-	for _, v := range s {
-		if v == str {
-			return true
-		}
-	}
-	return false
-}

taskfile/var.go

@@ -3,6 +3,7 @@ package taskfile
 import (
 	"errors"
 
+	"golang.org/x/exp/slices"
 	"gopkg.in/yaml.v3"
 )
 
@@ -59,7 +60,7 @@ func (vs *Vars) Set(key string, value Var) {
 	if vs.Mapping == nil {
 		vs.Mapping = make(map[string]Var, 1)
 	}
-	if !stringSliceContains(vs.Keys, key) {
+	if !slices.Contains(vs.Keys, key) {
 		vs.Keys = append(vs.Keys, key)
 	}
 	vs.Mapping[key] = value