Stop exposing libdiced_open_dice_nostd to //system/authgraph/tests

//system/authgraph/tests does not use this library.

Bug: 349524984
Test: atest libauthgraph_core_test
Change-Id: Iff41fd3956a5caf05d64aa1ad5af96aa1606c66d
diff --git a/libs/dice/open_dice/Android.bp b/libs/dice/open_dice/Android.bp
index 4904672..d614162 100644
--- a/libs/dice/open_dice/Android.bp
+++ b/libs/dice/open_dice/Android.bp
@@ -27,7 +27,6 @@
     ],
     visibility: [
         "//packages/modules/Virtualization:__subpackages__",
-        "//system/authgraph/tests:__subpackages__",
     ],
 }