marl: Remove the unittests from the Chromium build

Marl has its own repo and tests now, and so it is excessive to build and run these tests for downstream projects as well.

Bug: b/140546382
Change-Id: Ic79db961a3bfae072a56ffeb7052165c127538d3
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/36112
Reviewed-by: Ben Clayton <bclayton@google.com>
Tested-by: Ben Clayton <bclayton@google.com>
diff --git a/third_party/marl/BUILD.gn b/third_party/marl/BUILD.gn
index 1dcc08b..58821fe 100644
--- a/third_party/marl/BUILD.gn
+++ b/third_party/marl/BUILD.gn
@@ -70,22 +70,3 @@
     ":Marl_headers",
   ]
 }
-
-test("marl_unittests") {
-  sources = [
-    "src/conditionvariable_test.cpp",
-    "src/containers_test.cpp",
-    "src/defer_test.cpp",
-    "src/osfiber_test.cpp",
-    "src/pool_test.cpp",
-    "src/scheduler_test.cpp",
-    "src/ticket_test.cpp",
-    "src/waitgroup_test.cpp",
-    "src/marl_test.cpp",
-  ]
-  deps = [
-    ":Marl",
-    "//testing/gtest",
-    "//testing/gmock",
-  ]
-}