[nit] Update citation in README.md to v2.

README.md

@@ -131,7 +131,7 @@ Here is a sample `maven -f test .` command output to get valid `num_test_cases`:
 
 ```bibtex
 @misc{liu2025migrationbenchrepositorylevelcodemigration,
-      title={MIGRATION-BENCH: Repository-Level Code Migration Benchmark from Java 8},
+      title={MigrationBench: Repository-Level Code Migration Benchmark from Java 8},
       author={Linbo Liu and Xinle Liu and Qiang Zhou and Lin Chen and Yihan Liu and Hoan Nguyen and Behrooz Omidvar-Tehrani and Xi Shen and Jun Huan and Omer Tripp and Anoop Deoras},
       year={2025},
       eprint={2505.09569},
@@ -139,4 +139,4 @@ Here is a sample `maven -f test .` command output to get valid `num_test_cases`:
       primaryClass={cs.SE},
       url={https://arxiv.org/abs/2505.09569},
 }
-```
+```