chore: replace gopkg.in/yaml.v3 with go.yaml.in/yaml/v3

- gopkg.in/yaml.v3 is archived and unmaintained
- go.yaml.in/yaml/v3 is a compatible fork under the umbrella
  of https://yaml.org/

modules/markup/markdown/convertyaml.go

@@ -6,7 +6,7 @@ package markdown
 import (
 	"github.com/yuin/goldmark/ast"
 	east "github.com/yuin/goldmark/extension/ast"
-	"gopkg.in/yaml.v3"
+	"go.yaml.in/yaml/v3"
 )
 
 func nodeToTable(meta *yaml.Node) ast.Node {

modules/markup/markdown/meta.go

@@ -9,7 +9,7 @@ import (
 	"unicode"
 	"unicode/utf8"
 
-	"gopkg.in/yaml.v3"
+	"go.yaml.in/yaml/v3"
 )
 
 func isYAMLSeparator(line []byte) bool {

modules/markup/markdown/renderconfig.go

@@ -10,7 +10,7 @@ import (
 	"forgejo.org/modules/markup"
 
 	"github.com/yuin/goldmark/ast"
-	"gopkg.in/yaml.v3"
+	"go.yaml.in/yaml/v3"
 )
 
 // RenderConfig represents rendering configuration for this file

modules/markup/markdown/renderconfig_test.go

@@ -7,7 +7,7 @@ import (
 	"strings"
 	"testing"
 
-	"gopkg.in/yaml.v3"
+	"go.yaml.in/yaml/v3"
 )
 
 func TestRenderConfig_UnmarshalYAML(t *testing.T) {