getdeps: drop getdeps test, keep build

Summary:
Currently, getdeps build has 585 tests are failing on CI. Example:

  --- test-checkmessagehook.t
  +++ test-checkmessagehook.t.err
  @@ -10,32 +10,30 @@

     $ eagerepo
     $ sl init repo
  +  Creating a ".sl" repo with Git compatible storage. For full "git" compatibility, create repo using "git init". See https://sapling-scm.com/docs/git/git_support_modes for more information.sh: command not found: git
  +  abort: git clone was not successful
  +  [255]

Probably because my recent `setup.py` -> `build.py` migration. But I don't have
bandwidth to fix it now.

However, the getdeps *test* step:
- Took 35 minutes to run, is too slow.
  - Full job: 61 minutes.
  - Building fbthrift: 5 minutes.
  - Building rust-shed: 11 minutes. <- probably bad idea to build it in full
  - Building sapling: 4 minutes. <- this is actually fast
- Existing bash script in Makefile seems unmaintainable.
- Is too noisy and somewhat duplicates with buck tests.

If we want to restart testing in OSS, we should consider using a Python, not
bash script, and provide a way to bypass the getdeps C++ / cmake dependencies
if EdenFS is not needed.

Building via getdeps still seem to provide value, it can in theory detects
mis-use of cargo features. So I kept that for now.

Reviewed By: kavehahmadi60

Differential Revision: D107590021

fbshipit-source-id: b496cdd1cf41b3fd46f2a961adf73669c3ed0653

Author: quark-zju

build/fbcode_builder/manifests/sapling

@@ -25,9 +25,6 @@ getdepsbuild
 [make.install_args]
 install-getdeps
 
-[make.test_args]
-test-getdeps
-
 [shipit.pathmap]
 fbcode/configerator/structs/scm/hg = configerator/structs/scm/hg
 fbcode/configerator/structs/scm/hg/public_autocargo = configerator/structs/scm/hg