Cannot compare list of polynomials because of missing `rtoldefault` 

```julia
using DynamicPolynomials
@polyvar x
a = [2x, x^2]

# Fine to compare individual elements
@assert a[1] ≈ a[1] && a[2] == a[2]

# ERROR: MethodError: no method matching rtoldefault(...) 
a ≈ a
```