Replaced "use serde_derive::" with "use serde" in tests as the feature "serde/derive" is always enabled

Author: sammhicks

Cargo.toml

@@ -30,9 +30,6 @@ version = "0.3.5"
 default-features = false
 optional = true
 
-[dev-dependencies]
-serde_derive = "1.0.100"
-
 [features]
 default = ["heapless"]
 custom-error-messages = ["heapless"]

src/de/mod.rs

@@ -876,7 +876,7 @@ where
 
 #[cfg(test)]
 mod tests {
-    use serde_derive::Deserialize;
+    use serde::Deserialize;
 
     #[derive(Debug, Deserialize, PartialEq)]
     enum Type {

src/ser/mod.rs

@@ -713,7 +713,7 @@ impl ser::SerializeTupleVariant for Unreachable {
 
 #[cfg(test)]
 mod tests {
-    use serde_derive::Serialize;
+    use serde::Serialize;
 
     const N: usize = 128;
 
@@ -1031,7 +1031,7 @@ mod tests {
 
     #[test]
     fn test_tuple_struct_roundtrip() {
-        use serde_derive::Deserialize;
+        use serde::Deserialize;
 
         #[derive(Debug, Deserialize, Serialize, PartialEq, Eq)]
         struct A<'a>(u32, Option<&'a str>, u16, bool);