build: go 1.24

We were running behind and there were quite some deprecations to update.
This was mostly in the upstream copy/pasta package but seems quite
minimal.

vendor/go.opentelemetry.io/otel/sdk/resource/os_release_darwin.go

@@ -5,6 +5,7 @@ package resource // import "go.opentelemetry.io/otel/sdk/resource"
 
 import (
 	"encoding/xml"
+	"errors"
 	"fmt"
 	"io"
 	"os"
@@ -63,7 +64,7 @@ func parsePlistFile(file io.Reader) (map[string]string, error) {
 	}
 
 	if len(v.Dict.Key) != len(v.Dict.String) {
-		return nil, fmt.Errorf("the number of <key> and <string> elements doesn't match")
+		return nil, errors.New("the number of <key> and <string> elements doesn't match")
 	}
 
 	properties := make(map[string]string, len(v.Dict.Key))

vendor/go.opentelemetry.io/otel/sdk/resource/resource.go

@@ -21,11 +21,22 @@ import (
 // Resources should be passed and stored as pointers
 // (`*resource.Resource`).  The `nil` value is equivalent to an empty
 // Resource.
+//
+// Note that the Go == operator compares not just the resource attributes but
+// also all other internals of the Resource type. Therefore, Resource values
+// should not be used as map or database keys. In general, the [Resource.Equal]
+// method should be used instead of direct comparison with ==, since that
+// method ensures the correct comparison of resource attributes, and the
+// [attribute.Distinct] returned from [Resource.Equivalent] should be used for
+// map and database keys instead.
 type Resource struct {
 	attrs     attribute.Set
 	schemaURL string
 }
 
+// Compile-time check that the Resource remains comparable.
+var _ map[Resource]struct{} = nil
+
 var (
 	defaultResource     *Resource
 	defaultResourceOnce sync.Once
@@ -137,15 +148,19 @@ func (r *Resource) Iter() attribute.Iterator {
 	return r.attrs.Iter()
 }
 
-// Equal returns true when a Resource is equivalent to this Resource.
-func (r *Resource) Equal(eq *Resource) bool {
+// Equal returns whether r and o represent the same resource. Two resources can
+// be equal even if they have different schema URLs.
+//
+// See the documentation on the [Resource] type for the pitfalls of using ==
+// with Resource values; most code should use Equal instead.
+func (r *Resource) Equal(o *Resource) bool {
 	if r == nil {
 		r = Empty()
 	}
-	if eq == nil {
-		eq = Empty()
+	if o == nil {
+		o = Empty()
 	}
-	return r.Equivalent() == eq.Equivalent()
+	return r.Equivalent() == o.Equivalent()
 }
 
 // Merge creates a new [Resource] by merging a and b.