eth/fetcher: avoid hang in tests (partial fix for #23331) (#23351)

* eth/fetcher: fix test to avoid hanging. Partial fix for #23331

* eth/filters: avoid dangling goroutines

* eth/fetcher: revert closing of proceed

eth/fetcher/tx_fetcher_test.go

@@ -304,7 +304,6 @@ func TestTransactionFetcherSingletonRequesting(t *testing.T) {
 func TestTransactionFetcherFailedRescheduling(t *testing.T) {
 	// Create a channel to control when tx requests can fail
 	proceed := make(chan struct{})
-
 	testTransactionFetcherParallel(t, txFetcherTest{
 		init: func() *TxFetcher {
 			return NewTxFetcher(
@@ -1263,6 +1262,16 @@ func testTransactionFetcher(t *testing.T, tt txFetcherTest) {
 	fetcher.Start()
 	defer fetcher.Stop()
 
+	defer func() { // drain the wait chan on exit
+		for {
+			select {
+			case <-wait:
+			default:
+				return
+			}
+		}
+	}()
+
 	// Crunch through all the test steps and execute them
 	for i, step := range tt.steps {
 		switch step := step.(type) {