Remove SLSA prop from project model, not used and blocks upstream change

efservices/src/main/java/org/eclipsefoundation/efservices/api/models/Project.java

@@ -69,8 +69,6 @@ public abstract class Project {
 
     public abstract String getTopLevelProject();
 
-    public abstract Slsa getSlsa();
-
     @Memoized
     public Optional<Collaboration> getSpecWorkingGroup() {
         // stored as map as empty returns an array instead of a map
@@ -143,8 +141,6 @@ public abstract class Project {
 
         public abstract Builder setTopLevelProject(String project);
 
-        public abstract Builder setSlsa(Slsa slsa);
-
         public abstract Project build();
     }
 
@@ -307,24 +303,4 @@ public abstract class Project {
             public abstract Release build();
         }
     }
-
-    @AutoValue
-    @JsonDeserialize(builder = AutoValue_Project_Slsa.Builder.class)
-    public abstract static class Slsa {
-
-        public abstract String getBuildLevel();
-
-        public static Builder builder() {
-            return new AutoValue_Project_Slsa.Builder();
-        }
-
-        @AutoValue.Builder
-        @JsonPOJOBuilder(withPrefix = "set")
-        public abstract static class Builder {
-
-            public abstract Builder setBuildLevel(String buildLevel);
-
-            public abstract Slsa build();
-        }
-    }
 }