fix test to make it run in Ruby 3.4

Author: yukideluxe

spec/currency/heuristics_spec.rb

@@ -1,9 +1,7 @@
 describe Money::Currency::Heuristics do
   describe "#analyze_string" do
-    let(:it) { Money::Currency }
-
     it "it raises deprecation error" do
-      expect{ it.analyze('123') }.to raise_error(StandardError, 'Heuristics deprecated, add `gem "money-heuristics"` to Gemfile')
+      expect { Money::Currency.analyze('123') }.to raise_error(StandardError, 'Heuristics deprecated, add `gem "money-heuristics"` to Gemfile')
     end
   end
 end