move stencil to pod

[burn2delete]

Currently this tasks modifies the current global dependencies to pull in stencil, this breaks projects which also pull in stencil or set their own version.

Please refactor task to use pods, which to keep stencil dependency isolated, and add core.cache to excludes.

[seancorfield]

I've made you an Admin of boot-new. I no longer use Boot and don't really have time to maintain boot-new at this point. Let me know if you need any additional permissions or input.