Update serde tokenization

Recent Serde changes ([1], [2]) changed the internal representation of
enums, breaking our test.

[1]: serde-rs/serde#2496
[2]: serde-rs/serde#2505

Author: tgeoghegan

aggregator_api/src/lib.rs

@@ -1726,7 +1726,10 @@ mod tests {
                     len: 2,
                 },
                 Token::Str("type"),
-                Token::Str("DapAuth"),
+                Token::UnitVariant {
+                    name: "AuthenticationToken",
+                    variant: "DapAuth",
+                },
                 Token::Str("token"),
                 Token::Str("ZW5jb2RlZA"),
                 Token::StructEnd,
@@ -1841,7 +1844,10 @@ mod tests {
                     len: 2,
                 },
                 Token::Str("type"),
-                Token::Str("DapAuth"),
+                Token::UnitVariant {
+                    name: "AuthenticationToken",
+                    variant: "DapAuth",
+                },
                 Token::Str("token"),
                 Token::Str("Y29sbGVjdG9yLWFiY2RlZjAw"),
                 Token::StructEnd,
@@ -1852,7 +1858,10 @@ mod tests {
                     len: 2,
                 },
                 Token::Str("type"),
-                Token::Str("DapAuth"),
+                Token::UnitVariant {
+                    name: "AuthenticationToken",
+                    variant: "DapAuth",
+                },
                 Token::Str("token"),
                 Token::Str("Y29sbGVjdG9yLWFiY2RlZjAw"),
                 Token::StructEnd,