Fix uninitialized constant ActiveSupport::XmlMini::IsolatedExecutionState

After the move to Rails 7, the following error was causing tests to fail:
```
uninitialized constant ActiveSupport::XmlMini::IsolatedExecutionState
```

The solution was to explicitly require `active_support` before requiring the Hash and Array core extensions. This is the suggested approach given in the [Active Support documentation][1], but presumably the previous combination of Ruby and Rails was more forgiving of its omittance.

This change is based on the solution identified here:
rails/rails#43851 (comment)

[1]: https://guides.rubyonrails.org/active_support_core_extensions.html#stand-alone-active-support

Author: ollietreend

lib/govspeak.rb

@@ -1,3 +1,4 @@
+require "active_support"
 require "active_support/core_ext/hash"
 require "active_support/core_ext/array"
 require "erb"