Remove useless mts/mcts tags for CtsTetheringTest.

CtsTetheringTest only appears in mts-tethering-tests-list-user.xml
and not in any other test lists. So remove the MCTS tags that refer to
other MTS suites.

Bug: 369758357
Test: test-only change
Change-Id: Ib75f9c287e011b770bddeee4fba3e6f6f699a93a
diff --git a/tests/cts/tethering/Android.bp b/tests/cts/tethering/Android.bp
index 1165018..83818be 100644
--- a/tests/cts/tethering/Android.bp
+++ b/tests/cts/tethering/Android.bp
@@ -94,14 +94,8 @@
     // Tag this module as a cts test artifact
     test_suites: [
         "cts",
-        "mts-dnsresolver",
-        "mts-networking",
         "mts-tethering",
-        "mts-wifi",
-        "mcts-dnsresolver",
-        "mcts-networking",
         "mcts-tethering",
-        "mcts-wifi",
         "general-tests",
     ],