Fix wg.Wait / error check out of order

The loop starts a bunch of goroutines, so there's unlikely to be an error immediately. It needs to wait.

Not sure why I got this wrong lol

agent/artifact_uploader.go

@@ -116,15 +116,14 @@ func (a *ArtifactUploader) Collect(ctx context.Context) ([]*api.Artifact, error)
 		return nil, fmt.Errorf("getting working directory: %w", err)
 	}
 
-	var wg sync.WaitGroup
-
 	ac := &artifactCollector{
 		ArtifactUploader: a,
 		wd:               wd,
 		seenPaths:        make(map[string]bool),
 	}
 
 	wctx, cancel := context.WithCancelCause(ctx)
+	var wg sync.WaitGroup
 	for _, globPath := range strings.Split(a.conf.Paths, ArtifactPathDelimiter) {
 		globPath := strings.TrimSpace(globPath)
 		if globPath == "" {
@@ -140,13 +139,12 @@ func (a *ArtifactUploader) Collect(ctx context.Context) ([]*api.Artifact, error)
 			}
 		}()
 	}
+	wg.Wait()
+
 	if err := context.Cause(wctx); err != nil {
 		return nil, err
 	}
 
-	// Wait for workers to complete
-	wg.Wait()
-
 	return ac.artifacts, nil
 }