build: support older Go releases for OpenShift

go.mod

@@ -7,6 +7,7 @@ require (
 	github.com/moov-io/base v0.48.5
 	github.com/spf13/cobra v1.8.0
 	github.com/stretchr/testify v1.9.0
+	golang.org/x/exp v0.0.0-20231206192017-f3f8817b8deb
 	gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c
 )
 

go.sum

@@ -34,6 +34,8 @@ github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcU
 github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
 github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
 github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
+golang.org/x/exp v0.0.0-20231206192017-f3f8817b8deb h1:c0vyKkb6yr3KR7jEfJaOSv4lG7xPkbN6r52aJz1d8a8=
+golang.org/x/exp v0.0.0-20231206192017-f3f8817b8deb/go.mod h1:iRJReGqOEeBhDZGkGbynYwcHlctCvnjTYIamk7uXpHI=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=

pkg/file/file_instance.go

@@ -9,13 +9,14 @@ import (
 	"errors"
 	"fmt"
 	"reflect"
-	"slices"
 	"strings"
 	"unicode"
 
 	"github.com/moov-io/base/log"
 	"github.com/moov-io/metro2/pkg/lib"
 	"github.com/moov-io/metro2/pkg/utils"
+
+	"golang.org/x/exp/slices"
 )
 
 var _ File = (*fileInstance)(nil)