aead_fuzzing::Aead::new: Don't panic in release builds. (#1353)

The original rationale for this panic was to ensure we never ship
users a Firefox with a crypto-disabled version of aead. However, it is
common for Firefox fuzzing builds to be optimized: fuzzing is often
combined with LLVM's Address Sanitizer, whose docs recommend optimized
builds. Such Firefox builds crash the moment anything tries to
initialize Aead.

There are other safeguards in place that prevent Mozilla from shipping
fuzzing-enabled builds, so this one can be removed.

neqo-crypto/src/aead_fuzzing.rs

@@ -15,9 +15,6 @@ pub struct Aead {}
 #[allow(clippy::unused_self)]
 impl Aead {
     pub fn new(_version: Version, _cipher: Cipher, _secret: &SymKey, _prefix: &str) -> Res<Self> {
-        #[cfg(not(debug_assertions))]
-        panic!("Trying to run a non-debug fuzzing build.");
-
         Ok(Self {})
     }