[chore] update go-structr and go-mangler to no longer rely on modern-go/reflect2 (#3026)

* updates go-structr and go-mangler to no longer rely on modern-go/reflect2 (*phew* now we're go1.23 safe)

* update go-structr version

* bump go-structr to improve memory usage (v. slightly) in certain conditions

vendor/codeberg.org/gruf/go-structr/util.go

@@ -1,5 +1,7 @@
 package structr
 
+import "unsafe"
+
 // once only executes 'fn' once.
 func once(fn func()) func() {
 	var once int32
@@ -11,3 +13,9 @@ func once(fn func()) func() {
 		fn()
 	}
 }
+
+// eface_data returns the data ptr from an empty interface.
+func eface_data(a any) unsafe.Pointer {
+	type eface struct{ _, data unsafe.Pointer }
+	return (*eface)(unsafe.Pointer(&a)).data
+}