Fix while loop conditional.

Author: lohedges

src/somd2/runner/_runner.py

@@ -690,7 +690,7 @@ def generate_lam_vals(lambda_base, increment=0.001):
                         next_frame = self._config.frame_frequency
 
                         # Loop until we reach the runtime.
-                        while runtime <= checkpoint_frequency:
+                        while runtime < checkpoint_frequency:
                             # Run the dynamics in blocks of the GCMC frequency.
                             dynamics.run(
                                 self._config.gcmc_frequency,