airstore: remove getdeps manifest, getdeps sandcastle integration

Summary:
X-link: facebook/wangle#233

X-link: facebookexperimental/rust-shed#54

X-link: facebookincubator/hsthrift#132

X-link: facebookincubator/zstrong#846

takes AIRStore off of getdeps!
- remove our manifest file
- remove our native-getdeps sandcastle integration

Differential Revision: D57985865