Remove unused import from contract_id.sw (FuelLabs#4691)

## Description


## Checklist

- [ ] I have linked to any relevant issues.
- [ ] I have commented my code, particularly in hard-to-understand
areas.
- [ ] I have updated the documentation where relevant (API docs, the
reference, and the Sway book).
- [ ] I have added tests that prove my fix is effective or that my
feature works.
- [ ] I have added (or requested a maintainer to add) the necessary
`Breaking*` or `New Feature` labels where relevant.
- [ ] I have done my best to ensure that my PR adheres to [the Fuel Labs
Code Review
Standards](https://github.com/FuelLabs/rfcs/blob/master/text/code-standards/external-contributors.md).
- [x] I have requested a review from the relevant team or maintainers.

sway-lib-std/src/contract_id.sw

@@ -1,7 +1,6 @@
 //! A wrapper around the `b256` type to help enhance type-safety.
 library;
 
-use ::intrinsics::size_of_val;
 use ::convert::From;
 
 /// The `ContractId` type, a struct wrapper around the inner `b256` value.

sway-lsp/tests/lib.rs

@@ -1020,15 +1020,15 @@ async fn go_to_definition_for_consts() {
         req_uri: &uri,
         req_line: 9,
         req_char: 24,
-        def_line: 18,
+        def_line: 17,
         def_start_char: 5,
         def_end_char: 9,
         def_path: "sway-lib-std/src/contract_id.sw",
     };
     let _ = lsp::definition_check(&mut service, &contract_go_to, &mut i).await;
 
     contract_go_to.req_char = 34;
-    contract_go_to.def_line = 19;
+    contract_go_to.def_line = 18;
     contract_go_to.def_start_char = 7;
     contract_go_to.def_end_char = 11;
     let _ = lsp::definition_check(&mut service, &contract_go_to, &mut i).await;