cargo-deny: ignore instant and derivative unmaintained warnings (#3540)

Co-authored-by: Ameer Ghani <[email protected]>

deny.toml

@@ -7,6 +7,15 @@ all-features = true
 
 [advisories]
 version = 2
+ignore = [
+    # `instant` is unmaintained, but it is feature-complete and small, so it is unlikely to have
+    # bugs or security vulnerabilities.
+    "RUSTSEC-2024-0384",
+
+    # Use of `derivative` has been removed from production code. It still exists as transitive
+    # dependency on integration_tests.
+    "RUSTSEC-2024-0388"
+]
 
 [bans]
 multiple-versions = "allow"