Add missing lifetime annotation to EscapedStr::as_escaped_str (#3920)

`JsonTokenIterator` parses and returns `Token`s from a provided u8
slice. `EscapedStr` is used as a member field in several token variants,
such as `ObjectKey` and `ValueString`. While `as_escaped_str` returns a
reference to the underlying `&'a str`, the lifetime annotation was
missing from its return type.

This PR adds the missing lifetime annotation.

Co-authored-by: Fahad Zubair <[email protected]>

Author: drganjoo

rust-runtime/aws-smithy-json/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "aws-smithy-json"
-version = "0.60.7"
+version = "0.61.1"
 authors = ["AWS Rust SDK Team <[email protected]>", "John DiSanti <[email protected]>"]
 description = "Token streaming JSON parser for smithy-rs."
 edition = "2021"

rust-runtime/aws-smithy-json/src/deserialize/token.rs

@@ -25,7 +25,7 @@ impl<'a> EscapedStr<'a> {
     }
 
     /// Returns the escaped string value
-    pub fn as_escaped_str(&self) -> &str {
+    pub fn as_escaped_str(&self) -> &'a str {
         self.0
     }