PHOENIX — A San Diego Padres starting pitcher will allow a hit this season. It just hasn’t happened yet. Sean Manaea threw seven hitless innings Friday in his Padres debut, a day after Yu Darvish went six hitless innings in Thursday’s season opener. The no-hitter was not intact for long after Manaea departed, but the Padres bullpen this time did protect a lead to the end, as the Padres beat the Diamondbacks 3-0 at Chase Field. Whenever the hitless streak ends — and Joe Musgrove starts Saturday on the one-year anniversary of his throwing the only no-hitter in franchise history — what can be sai…