Fix build warnings + clippy errors from latest nightly

.gitlab-ci.yml

@@ -330,7 +330,7 @@ fuzz-tests:
     <<:                              *docker-env
     variables:
         # The QUICKCHECK_TESTS default is 100
-        QUICKCHECK_TESTS:            50000
+        QUICKCHECK_TESTS:            40000
     rules:
         - if: $CI_PIPELINE_SOURCE == "schedule"
         - if: $CI_COMMIT_REF_NAME == "master"

crates/env/src/chain_extension.rs

@@ -269,7 +269,7 @@ where
                 self.func_id,
                 input,
                 ErrorCode::from_status_code,
-                |output| scale::Decode::decode(&mut &output[..]).map_err(Into::into),
+                |mut output| scale::Decode::decode(&mut output).map_err(Into::into),
             )
         })
     }
@@ -323,7 +323,7 @@ where
                 self.func_id,
                 input,
                 |_status_code| Ok(()),
-                |output| scale::Decode::decode(&mut &output[..]).map_err(Into::into),
+                |mut output| scale::Decode::decode(&mut output).map_err(Into::into),
             )
         })
     }
@@ -380,8 +380,8 @@ where
                 self.func_id,
                 input,
                 ErrorCode::from_status_code,
-                |output| {
-                    let decoded = <O as scale::Decode>::decode(&mut &output[..])
+                |mut output| {
+                    let decoded = <O as scale::Decode>::decode(&mut output)
                         .expect("encountered error while decoding chain extension method call return value");
                     Ok(decoded)
                 },
@@ -429,8 +429,8 @@ where
                 self.func_id,
                 input,
                 |_status_code| Ok(()),
-                |output| {
-                    let decoded = <O as scale::Decode>::decode(&mut &output[..])
+                |mut output| {
+                    let decoded = <O as scale::Decode>::decode(&mut output)
                         .expect("encountered error while decoding chain extension method call return value");
                     Ok(decoded)
                 },

crates/env/src/engine/off_chain/impls.rs

@@ -205,12 +205,12 @@ impl EnvBackend for EnvInstance {
         D: FnOnce(&[u8]) -> ::core::result::Result<T, E>,
     {
         let encoded_input = input.encode();
-        let (status_code, output) = self
+        let (status_code, mut output) = self
             .chain_extension_handler
             .eval(func_id, &encoded_input)
             .expect("encountered unexpected missing chain extension method");
         status_to_result(status_code)?;
-        let decoded = decode_to_result(&mut &output[..])?;
+        let decoded = decode_to_result(&mut output)?;
         Ok(decoded)
     }
 }
@@ -277,7 +277,7 @@ impl EnvInstance {
             beneficiary,
             transferred: all,
         };
-        panic!(scale::Encode::encode(&res));
+        std::panic::panic_any(scale::Encode::encode(&res))
     }
 }