Suppress Style/ExplicitBlockArgument's offenses

Follow rubocop/rubocop#8415

This commit suppresses the following `Style/ExplicitBlockArgument`'s
offenses.

```console
% bundle exec rake
(snip)

Offenses:

lib/rubocop/rails/schema_loader/schema.rb:105:13: C:
Style/ExplicitBlockArgument: Consider using explicit block argument in
the surrounding method's signature over yield.
            node.body.children.each do |child| ...
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

181 files inspected, 1 offense detected
RuboCop failed!
```

lib/rubocop/rails/schema_loader/schema.rb

@@ -97,14 +97,12 @@ def build_indices(node)
           end.compact
         end
 
-        def each_content(node)
+        def each_content(node, &block)
           return enum_for(__method__, node) unless block_given?
 
           case node.body&.type
           when :begin
-            node.body.children.each do |child|
-              yield(child)
-            end
+            node.body.children.each(&block)
           else
             yield(node.body)
           end