[Feature Request] Add `Assert` function.

[l0kix2]

What problem are you trying to solve?

It seems since go 1.23.0 go vet has new warning

printf: non-constant format string in call to (*github.com/kinbiko/jsonassert.Asserter).Assertf (govet)
	ja.Assertf(
...

if format-like function is used without var args.
Since jsonasert only has Assertf(not Assert) it is also used if no arguments need to be passed govet warns for all such Assertf usages and I haven't find a way to configure govet/printf linter to ignore particular Assertf function.

Maybe correct way here is to have Assert function for such cases.