Fix unprepared_statement to work it when nesting

[kamipo]

I've been reported a problem by @osyo-manga, preloading queries in
unprepared_statement doesn't work as expected in main branch (queries
are executed as prepared statements).

It is caused by #41385, due to scope.to_sql in grouping_key depends
on unprepared_statement which has an issue when nesting.

To fix the issue, don't add/delete object_id in the prepared statements
disabled cache if that is already disabled.

[dla-c-box]

To save some investigation to other researchers, this patch can also fix new errors such as ActiveRecord::StatementInvalid PG::ProtocolViolation: ERROR: bind message supplies 0 parameters, but prepared statement "" requires 2 when migrating to a lower Rails version that doesn't contain this PR's patch, e.g. if using the method .with from the gem postgres_ext (CTE aren't available natively until Rails 7.1): it uses .to_sql to build its arel, so if you call .to_sql on a relation that uses .with, you end up with nested unprepared_statement and hit the problem this PR fixes (if you were to use the output of your .to_sql call as a component of another query, you'd end up with bind parameters where none are expected, hence the StatementInvalid).

Note: .to_sql is generated as unprepared_statement since Rails 5.1: 3befc7a

Before this fix (notice the "$1" in the generated string):

puts User.with(test: User.limit(1)).limit(1).to_sql
--> WITH "test" AS (SELECT "public"."users".* FROM "public"."users" LIMIT 1) SELECT "public"."users".* FROM "public"."users" LIMIT $1

After this fix:

puts User.with(test: User.limit(1)).limit(1).to_sql
--> WITH "test" AS (SELECT "public"."users".* FROM "public"."users" LIMIT 1) SELECT "public"."users".* FROM "public"."users" LIMIT 1