Don't show a deprecation warning for EnsureNode#branch just yet

There currently is no RuboCop version that will not show this warning.

changelog/fix_dont_emit_deprecation_just_yet.md

@@ -0,0 +1 @@
+* [#339](https://github.com/rubocop/rubocop-ast/pull/339): Do not emit a deprecation warning for `EnsureNode#body` to give RuboCop a chance to update its usage. `EnsureNode#body` will still be changed in the next major version of `rubocop-ast`. ([@earlopain][])

lib/rubocop/ast/node/ensure_node.rb

@@ -6,24 +6,11 @@ module AST
     # node when the builder constructs the AST, making its methods available
     # to all `ensure` nodes within RuboCop.
     class EnsureNode < Node
-      DEPRECATION_WARNING_LOCATION_CACHE = [] # rubocop:disable Style/MutableConstant
-      private_constant :DEPRECATION_WARNING_LOCATION_CACHE
-
       # Returns the body of the `ensure` clause.
       #
       # @return [Node, nil] The body of the `ensure`.
       # @deprecated Use `EnsureNode#branch`
       def body
-        first_caller = caller(1..1).first
-
-        unless DEPRECATION_WARNING_LOCATION_CACHE.include?(first_caller)
-          warn '`EnsureNode#body` is deprecated and will be changed in the next major version of ' \
-               'rubocop-ast. Use `EnsureNode#branch` instead to get the body of the `ensure` branch.'
-          warn "Called from:\n#{caller.join("\n")}\n\n"
-
-          DEPRECATION_WARNING_LOCATION_CACHE << first_caller
-        end
-
         branch
       end