feat: switch to assimilated binaries

Assimilated binaries are converted from a "fat" APE into a native
binary for the provided host.

This change means that the APE binaries are completely hermetic
binaries that do not require their own launcher, shell script or
anything else.

This solves a huge bootstrapping problem that POSIX shell scripts
need runfiles but to effectively find the runfiles one needs POSIX
tooling to resolve symlinks, etc.

Having a single executable to rely on solves the need for runfiles.