proc: fix runtime type handling for Go 1.21 (#3370)

Go 1.21 renamed runtime._type to internal/abi.Type and changed the name
of its fields. Update Delve so that it uses the new names for loading
interfaces and generic type parameters.

_scripts/rtype-out.txt

@@ -15,7 +15,7 @@ type bmap struct {
 }
 
 type eface struct {
-	_type *_type
+	_type *_type|*internal/abi.Type
 	data unsafe.Pointer
 }
 
@@ -50,7 +50,7 @@ type iface struct {
 }
 
 type itab struct {
-	_type *_type
+	_type *_type|*internal/abi.Type
 }
 
 type moduledata struct {