Remove duplicate screenshot_tests target

Summary:
There is already a target which exports pretty much this exact
set of files. Use that instead.

Reviewed By: xiphirx

Differential Revision: D14686541

fbshipit-source-id: e355d6c4986008223823a055d6886cd635c725b7

plugin/src/py/BUCK

@@ -1,11 +1,5 @@
 load("@fbsource//tools/build_defs:fb_native_wrapper.bzl", "fb_native")
 
-fb_native.python_library(
-    name = "screenshot_tests",
-    srcs = glob(["**/*.py"]),
-    visibility = ["PUBLIC"],
-)
-
 fb_native.python_library(
     name = "android_screenshot_tests",
     srcs = glob(["android_screenshot_tests/**/*.py"]),