Fix model-manual's use of contexts

Author: mhauru

developers/compiler/model-manual/index.qmd

@@ -33,21 +33,21 @@ Taking the `gdemo` model above as an example, the macro-based definition can be
 using DynamicPPL
 
 # Create the model function.
-function gdemo2(model, varinfo, context, x)
+function gdemo2(model, varinfo, x)
     # Assume s² has an InverseGamma distribution.
     s², varinfo = DynamicPPL.tilde_assume!!(
-        context, InverseGamma(2, 3), @varname(s²), varinfo
+        model.context, InverseGamma(2, 3), @varname(s²), varinfo
     )
 
     # Assume m has a Normal distribution.
     m, varinfo = DynamicPPL.tilde_assume!!(
-        context, Normal(0, sqrt(s²)), @varname(m), varinfo
+        model.context, Normal(0, sqrt(s²)), @varname(m), varinfo
     )
 
     # Observe each value of x[i] according to a Normal distribution.
     for i in eachindex(x)
         _retval, varinfo = DynamicPPL.tilde_observe!!(
-            context, Normal(m, sqrt(s²)), x[i], @varname(x[i]), varinfo
+            model.context, Normal(m, sqrt(s²)), x[i], @varname(x[i]), varinfo
         )
     end