remove unused constraints

Author: yngrtc

Cargo.lock

@@ -1,6 +1,5 @@
 [workspace]
 members = [
-    "constraints",
     "data",
     "dtls",
     "examples",
@@ -20,8 +19,5 @@ members = [
 ]
 resolver = "2"
 
-[workspace.lints.rust]
-unexpected_cfgs = { level = "warn", check-cfg = ['cfg(fuzzing)'] }
-
 [profile.dev]
 opt-level = 0