Remove 'realtwin' software citation

Removed citation for the 'realtwin' software from README.

Author: xyluo25

README.md

@@ -154,13 +154,4 @@ year = {2025},
 month = {jun}
 }
 
-@software{luo2025realtwin,
-author = {Luo, Xiangyong and Xu, Guanhao and Saroj, Abhilasha and Yuan, Jinghui and Shao, Yunli and Wang, Chieh (Ross)},
-doi = {https://doi.org/10.11578/dc.20250602.3},
-month = jun,
-title = {realtwin: A Unified Simulation Scenario Generation Tool for Mobility Research},
-url = {https://github.com/ORNL-Real-Sim/Real-Twin},
-version = {0.1.0},
-year = {2025}
-}
 ```