delay unsplit flux pulses according to their start

src/qibolab/instruments/zhinst/executor.py

@@ -565,6 +565,7 @@ def select_exp(self, exp, qubits, exp_options):
         with exp.section(uid="unsplit_channels"):
             for ch in self.unsplit_channels:
                 for pulse in self.sequence[ch]:
+                    exp.delay(signal=ch, time=pulse.pulse.start)
                     self.play_sweep(exp, ch, pulse)
 
         weights = {}