Agnostic means anything from “I am pretty sure there is no creator God but I cannot 100% prove that” (and in that sense Dawkins calls himself an agnostic).
To “I am going to live as if there is a creator God but I am not 100% sure there is one.”
Calling oneself an agnostic pantheist would mean that you are (say) 99% pantheist but not absolutely sure (or unable to prove that) there is no creator God.
Personally I can’t prove there is no creator God – nobody can – but I am not going to call myself an agnostic just on that account. There are gazillions of improbable things that I cannot prove – eg I can’t prove that the moon is not made of cheese cunningly disguised to make it look like rock.
I am a scientific pantheist.
Identifying yourself an agnostic is okay if you like it, but it means identifying your spirituality by one specific thing you are not sure about.
Just as identifying as an atheist is identifying yourself primarily by one specific thing you do not believe in.