feat: enhance concurrency management by adding WaitGroup support in extractors and loaders

cmd/go_migrate/loader-error-handler.go

@@ -3,6 +3,7 @@ package main
 import (
 	"context"
 	"fmt"
+	"sync"
 )
 
 type LoaderError struct {
@@ -19,6 +20,7 @@ func loaderErrorHandler(
 	chErrorsIn <-chan LoaderError,
 	chChunksOut chan<- Chunk,
 	chJobErrorsOut chan<- JobError,
+	wgActiveChunks *sync.WaitGroup,
 ) {
 	for {
 		if ctx.Err() != nil {
@@ -46,6 +48,8 @@ func loaderErrorHandler(
 				case <-ctx.Done():
 					return
 				}
+
+				wgActiveChunks.Done()
 				continue
 			}