all: apply modernisers

Signed-off-by: Ophestra <cat@gensokyo.uk>

internal/outcome/process.go

@@ -328,11 +328,11 @@ func (k *outcome) main(msg message.Msg, identifierFd int) {
 				}
 
 				if err := k.sys.Revert((*system.Criteria)(&ec)); err != nil {
-					var joinError interface {
+					joinError, ok := errors.AsType[interface {
 						Unwrap() []error
 						error
-					}
-					if !errors.As(err, &joinError) || joinError == nil {
+					}](err)
+					if !ok || joinError == nil {
 						perror(err, "revert system setup")
 					} else {
 						for _, v := range joinError.Unwrap() {