chore: update generic type constraints

Author: raimundo-henriques

gen/src/pact_integration.rs

@@ -6,6 +6,7 @@ use pact_data_model::{
     ProductIdSet, SpecVersionString, Urn, VersionInteger,
 };
 use rust_decimal::Decimal;
+use schemars::JsonSchema;
 use serde::Serialize;
 use uuid::Uuid;
 
@@ -113,6 +114,7 @@ pub fn to_pcf<T>(
     characterization_factors: Option<Vec<CharacterizationFactors>>,
 ) -> ProductFootprint<T>
 where
+    T: JsonSchema,
     T: Serialize,
     PactMappedFields: for<'a> From<&'a T>,
 {