Copy in the only thing we were using golang/x/exp for (#1040)

go.mod

@@ -36,7 +36,6 @@ require (
 	go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.22.0
 	go.opentelemetry.io/otel/sdk v1.22.0
 	go.opentelemetry.io/otel/trace v1.22.0
-	golang.org/x/exp v0.0.0-20240119083558-1b970713d09a
 	golang.org/x/mod v0.14.0
 	golang.org/x/time v0.5.0
 	golang.org/x/tools v0.17.0
@@ -122,6 +121,7 @@ require (
 	go.uber.org/atomic v1.9.0 // indirect
 	go.uber.org/multierr v1.9.0 // indirect
 	golang.org/x/crypto v0.18.0 // indirect
+	golang.org/x/exp v0.0.0-20240119083558-1b970713d09a // indirect
 	golang.org/x/net v0.20.0 // indirect
 	golang.org/x/oauth2 v0.15.0 // indirect
 	golang.org/x/sync v0.6.0 // indirect

internal/app/dashboard_store.go

@@ -11,7 +11,6 @@ import (
 	"github.com/ministryofjustice/opg-modernising-lpa/internal/actor"
 	"github.com/ministryofjustice/opg-modernising-lpa/internal/dynamo"
 	"github.com/ministryofjustice/opg-modernising-lpa/internal/page"
-	"golang.org/x/exp/maps"
 )
 
 // An lpaLink is used to join an actor to an LPA.
@@ -179,8 +178,8 @@ func (s *dashboardStore) GetAll(ctx context.Context) (donor, attorney, certifica
 		}
 	}
 
-	certificateProvider = maps.Values(certificateProviderMap)
-	attorney = maps.Values(attorneyMap)
+	certificateProvider = mapValues(certificateProviderMap)
+	attorney = mapValues(attorneyMap)
 
 	byUpdatedAt := func(a, b page.LpaAndActorTasks) int {
 		if a.Donor.UpdatedAt.After(b.Donor.UpdatedAt) {
@@ -195,3 +194,11 @@ func (s *dashboardStore) GetAll(ctx context.Context) (donor, attorney, certifica
 
 	return donor, attorney, certificateProvider, nil
 }
+
+func mapValues[M ~map[K]V, K comparable, V any](m M) []V {
+	r := make([]V, 0, len(m))
+	for _, v := range m {
+		r = append(r, v)
+	}
+	return r
+}