Add an invokelatest that may be required in 1.12 (#231)

This test currently relies on implicit world age increments at top
level. We're re-evaluating where these go because julia is currently
inconsistent about it in the interpreter, compiler and inference.
To make sure this test keeps working on 1.12, add an explicit
world age increment. See JuliaLang/julia#56509.

test/runtests.jl

@@ -154,6 +154,10 @@ end
     # skip tables containing only unipotent character types
     startswith(table, "uni") && continue
 
-    @test order(g) == sum(number_of_characters(c) * degree(c)^2 for c in g)
+    # Workaround that may be needed in Julia >= 1.12. Can be removed
+    # when we manage to remove the need for `eval` when loading tables.
+    Base.invokelatest() do
+      @test order(g) == sum(number_of_characters(c) * degree(c)^2 for c in g)
+    end
   end
 end