[libc++] Remove unused Python imports (#73724)

VSCode's Pylance extension informed me, and text searching confirmed,
that these imports are unused. I believe we should be able to remove
them harmlessly.
diff --git a/libcxx/utils/adb_run.py b/libcxx/utils/adb_run.py
index b54198f..dc15b51 100755
--- a/libcxx/utils/adb_run.py
+++ b/libcxx/utils/adb_run.py
@@ -18,7 +18,7 @@
 import socket
 import subprocess
 import sys
-from typing import List, Optional, Tuple
+from typing import List, Tuple
 
 
 # Sync a host file /path/to/dir/file to ${REMOTE_BASE_DIR}/run-${HASH}/dir/file.