Fix remaining wsl_v5 whitespace findings (refs #61)

Insert the blank line wsl_v5 requires above `defer` and `go`
statements that share no variables with the statement above them.
Applied mechanically via `make lint-fix`; the diff is 60 added blank
lines and nothing else.

internal/s3/client_test.go

@@ -12,6 +12,7 @@ import (
 //nolint:paralleltest // test servers share a fixed localhost port
 func TestClient(t *testing.T) {
 	ts := NewTestServer(t)
+
 	defer func() {
 		err := ts.Cleanup()
 		if err != nil {
@@ -58,6 +59,7 @@ func verifyPutGetHead(
 	if err != nil {
 		t.Fatalf("failed to get object: %v", err)
 	}
+
 	defer func() {
 		err := reader.Close()
 		if err != nil {