Not entirely on NASA, Congress slashed their budget causing a -$500M hole, with future years budget not looking to fare much better so they had to make some tough decisions. Sounds like other missions in the same program are going to pick up VIPER's objectives though.
Sure looks like they cut it 2% in 2024, but they've increased it every year over the last 10 years, even in real terms (maybe 2022/2023 was a bit under flat)
The problem is that most of that budget is earmarked for huge money-wasters like SLS, and those earmarks are growing. So the non-earmarked budget shrinks.
In real terms that looks pretty flat for both the last 10 years and since the beginning of the list. Doesn't explain the project cut but also isn't really real budget growth either.