[Bug]: "Live" spending reports don't update automatically after #7672

### What happened?

#7672 has broken the "live" status of the spending reports, no longer switching automatically to the current month.

Expected: Live reports automatically switch to the current month when the month rolls over
Actual: Spending reports now compare the month they were initially set up with (they behave like static)

Net worth and other report cards work like expected:

This is on version v26.6.0

### How can we reproduce the issue?

- Create a spending report as "Live"
- Choose "Budgeted" or "Average" (not sure about "Single month")
- let the month roll over
- current month does not change

Recreate above steps on an earlier build (v26.5.0 or earlier) and notice the difference in beahivor

### Where are you hosting Actual?

Docker

### What browsers are you seeing the problem on?

Chrome

### Operating System

Windows 11