Update num-bigint to 0.4.3

Test: cd external/rust/crates && atest --host -c
Change-Id: I51eaa561a1cfa983aaf0951b05db1a980af45b3a
diff --git a/METADATA b/METADATA
index 8ce088c..e0e6f54 100644
--- a/METADATA
+++ b/METADATA
@@ -7,13 +7,13 @@
   }
   url {
     type: ARCHIVE
-    value: "https://static.crates.io/crates/num-bigint/num-bigint-0.4.2.crate"
+    value: "https://static.crates.io/crates/num-bigint/num-bigint-0.4.3.crate"
   }
-  version: "0.4.2"
+  version: "0.4.3"
   license_type: NOTICE
   last_upgrade_date {
-    year: 2021
-    month: 9
-    day: 22
+    year: 2022
+    month: 3
+    day: 1
   }
 }