internal/rosa/package: migrate perl interpreter

Packages will be migrated separtely.

Signed-off-by: Ophestra <cat@gensokyo.uk>

internal/rosa/state.go

@@ -678,6 +678,8 @@ func (ctx *evalContext) pf(
 		helper  Helper
 
 		inputs, runtimes azalea.Array
+
+		anityaFallback bool
 	)
 	if err = args.Apply(map[unique.Handle[azalea.Ident]]any{
 		k("description"): &meta.Description,
@@ -698,6 +700,8 @@ func (ctx *evalContext) pf(
 		k("exec"):    &helper,
 		k("inputs"):  &inputs,
 		k("runtime"): &runtimes,
+
+		k("anityaFallback"): &anityaFallback,
 	}); err != nil {
 		return
 	}
@@ -727,6 +731,9 @@ func (ctx *evalContext) pf(
 	}
 
 	meta.ID = int(anitya)
+	if anityaFallback {
+		meta.latest = (*Versions).getStable
+	}
 	var source pkg.Artifact
 	switch p := sourceA.(type) {
 	case pkg.Artifact: