fix: string_to_string lint is now part of implicit_clone (#2173)

Cargo.toml

@@ -107,6 +107,7 @@ empty_line_after_doc_comments = "warn"
 equatable_if_let = "warn"
 fn_to_numeric_cast_any = "warn"
 format_push_string = "warn"
+implicit_clone = "warn"
 map_err_ignore = "warn"
 missing_const_for_fn = "warn"
 mixed_read_write_in_expression = "warn"
@@ -118,6 +119,5 @@ redundant_type_annotations = "warn"
 rest_pat_in_fully_bound_structs = "warn"
 string_lit_chars_any = "warn"
 string_slice = "warn"
-string_to_string = "warn"
 unnecessary_self_imports = "warn"
 use_self = "warn"