fix potential windows issue during copying

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>
Signed-off-by: Jan Braje <12571346+janluak@users.noreply.github.com>

pkg/cmd/bump_test.go

@@ -39,12 +39,14 @@ func TestBump(t *testing.T) {
 	if err != nil {
 		t.Fatalf("error on creating test file: %v", err)
 	}
-	defer destFileHandle.Close()
 
 	_, err = io.Copy(destFileHandle, srcFile)
 	if err != nil {
 		t.Fatalf("error on copying test file: %v", err)
 	}
+	if err := destFileHandle.Close(); err != nil {
+		t.Fatalf("error on closing test file: %v", err)
+	}
 
 	tests := []cmdTestCase{{
 		name:      "no args",