MDEV-35363 Avoid cloning of table statistics while saving the InnoDB table stats

[Thirunarayanan]

• The Jira issue number for this PR is: MDEV-32667

Description

• While saving the InnoDB table statistics, InnoDB does clone
  the table object and its statistics to protect the metadata
  in case if table is being dropped. From 10.6 onwards, any
  background task inside InnoDB on the table takes MDL.
  So metadata is protected by MDL of the table. Avoid the
  cloning of the table and its associated index statistics.

How can this PR be tested?

./mtr --suite=innodb

Basing the PR against the correct MariaDB version

• This is a new feature or a refactoring, and the PR is based against the main branch.
• This is a bug fix, and the PR is based against the earliest maintained branch in which the bug can be reproduced.

PR quality check

• I checked the CODING_STANDARDS.md file and my PR conforms to this where appropriate.
• For any trivial modifications to the PR, I am ok with the reviewer making the changes themselves.

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[dr-m]

Please push #3614 first, and rebase this once that fix has been merged to 10.6.

For clarity, please file this cleanup as a MDEV. It is not actually fixing what the title says, but removing some code that I had forgotten to remove in 45a05fd.

[dr-m]

Thank you, this looks good. I would also suggest removing the test that was added in #3616.