chore: Switch to maintained yaml library

Signed-off-by: Manuel Rüger <manuel@rueg.eu>

e2e/go.mod

@@ -129,6 +129,7 @@ require (
 	go.opentelemetry.io/proto/otlp v1.9.0 // indirect
 	go.uber.org/automaxprocs v1.6.0 // indirect
 	go.yaml.in/yaml/v2 v2.4.2 // indirect
+	go.yaml.in/yaml/v3 v3.0.4 // indirect
 	golang.org/x/crypto v0.46.0 // indirect
 	golang.org/x/exp v0.0.0-20250620022241-b7579e27df2b // indirect
 	golang.org/x/net v0.48.0 // indirect

go.mod

@@ -44,6 +44,7 @@ require (
 	go.opentelemetry.io/otel/sdk v1.39.0
 	go.opentelemetry.io/otel/trace v1.39.0
 	go.uber.org/automaxprocs v1.6.0
+	go.yaml.in/yaml/v3 v3.0.4
 	golang.org/x/net v0.48.0
 	golang.org/x/sync v0.19.0
 	golang.org/x/text v0.32.0
@@ -51,7 +52,6 @@ require (
 	google.golang.org/grpc v1.78.0
 	google.golang.org/protobuf v1.36.11
 	gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c
-	gopkg.in/yaml.v3 v3.0.1
 	oras.land/oras-go/v2 v2.6.0
 	sigs.k8s.io/yaml v1.6.0
 )
@@ -116,7 +116,6 @@ require (
 	go.opentelemetry.io/otel/metric v1.39.0 // indirect
 	go.opentelemetry.io/proto/otlp v1.9.0 // indirect
 	go.yaml.in/yaml/v2 v2.4.2 // indirect
-	go.yaml.in/yaml/v3 v3.0.4 // indirect
 	golang.org/x/crypto v0.46.0 // indirect
 	golang.org/x/mod v0.30.0 // indirect
 	golang.org/x/sys v0.39.0 // indirect

v1/ast/parser.go

@@ -20,7 +20,7 @@ import (
 	"strings"
 	"unicode/utf8"
 
-	"gopkg.in/yaml.v3"
+	"go.yaml.in/yaml/v3"
 
 	"github.com/open-policy-agent/opa/v1/ast/internal/scanner"
 	"github.com/open-policy-agent/opa/v1/ast/internal/tokens"

v1/test/cases/internal/fmtcases/main.go

@@ -15,7 +15,7 @@ import (
 	"github.com/open-policy-agent/opa/v1/format"
 	"github.com/open-policy-agent/opa/v1/test/cases"
 	"github.com/open-policy-agent/opa/v1/util"
-	"gopkg.in/yaml.v3"
+	"go.yaml.in/yaml/v3"
 )
 
 func main() {