There are a lot of circuits in there! Another possibility may deserve a mention: maybe you can identify a few that could be combined, for example that primarily serve lighting which has been converted to LED and draws mere amps. You could take a pair of 15 amp circuits and with a pigtail feed them both from a single 15 A breaker. Could do likewise with a pair of 20 amp circuits fed from a single 20 A breaker. That frees up one slot. Find another pairing and you've got the two slots you needed.
Just to be clear: it's generally OK to shuffle the single-pole circuits around the panel (but don't forget to update the legend). You could pick two that are on single breakers anywhere in the panel, or two that are on tandems, or two where one is on a tandem and the other is on a single breaker. If at any point you end up with a tandem breaker that's unused, pick a circuit from a single breaker and move it to that tandem.
One would have to take special care if the combining involved any multi-wire branch circuits (could combine a third circuit with either side of the MWBC, but cannot combine the two sides of MWBC into a single breaker/pole). It appears there are none of those in your panel so this caution is just for the benefit of future readers.