hooks_tests: Move plugin dependency from deps to runtime_deps

The hooks__plugin dependency is incorrectly declared as compiled
dependency, even though it is only runtime dependency. This was flagged
by unused_deps utility.

Change-Id: Icb8fd3d5e2397c58cc696ba453a3b72c80cb3b79

BUILD

diff --git a/BUILD b/BUILD
index cfdc295..35312a7 100644
--- a/BUILD
+++ b/BUILD
@@ -16,7 +16,6 @@
     srcs = glob(["src/test/java/**/*.java"]),
     tags = ["hooks"],
     visibility = ["//visibility:public"],
-    deps = PLUGIN_TEST_DEPS + PLUGIN_DEPS + [
-        ":hooks__plugin",
-    ],
+    runtime_deps = [":hooks__plugin"],
+    deps = PLUGIN_TEST_DEPS + PLUGIN_DEPS,
 )