Remove explicit inclusions of now-default modules

These modules are used by default in version 1.12.14 and so we were
getting deprecation warnings:

```
DEPRECATION WARNING: GraphQL::Execution::Interpreter is now the
default; remove `use GraphQL::Execution::Interpreter` from the schema
definition (app/graphql/consul_schema.rb:6)
DEPRECATION WARNING: GraphQL::Analysis::AST is now the default; remove
`use GraphQL::Analysis::AST` from the schema definition
(app/graphql/consul_schema.rb:7)
DEPRECATION WARNING: GraphQL::Pagination::Connections is now the
default, remove `use GraphQL::Pagination::Connections` from
app/graphql/consul_schema.rb:10
```

app/graphql/consul_schema.rb

@@ -1,11 +1,4 @@
 class ConsulSchema < GraphQL::Schema
   mutation(Types::MutationType)
   query(Types::QueryType)
-
-  # Opt in to the new runtime (default in future graphql-ruby versions)
-  use GraphQL::Execution::Interpreter
-  use GraphQL::Analysis::AST
-
-  # Add built-in connections for pagination
-  use GraphQL::Pagination::Connections
 end