executor: fix prepared protocol charset (#58872)

[ti-chi-bot]

This is an automated cherry-pick of #58872

What problem does this PR solve?

Issue Number: close #58870

Problem Summary:

When it is text-prepare, SQL will be parsed twice. The first time, it is already transformed to utf8 due to charset_client. Thus when it comes to executor, only the other two parameters need to set.

But if it is coming from prepare protocol, SQL have not been parsed before. We also need to set charset_client to transform it to utf8.

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)
• No need to test

  • I checked and no code files have been changed.

Side effects

• Performance regression: Consumes more CPU
• Performance regression: Consumes more Memory
• Breaking backward compatibility

Documentation

• Affects user behaviors
• Contains syntax changes
• Contains variable changes
• Contains experimental features
• Changes MySQL compatibility

Release note

Please refer to Release Notes Language Style Guide to write a quality release note.

Fix broken prepare protocol when charset_client is not UTF8

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: Defined2014, tangenta

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [Defined2014,tangenta]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2025-02-06 02:19:04.85918299 +0000 UTC m=+324616.391594973: ☑️ agreed by Defined2014.
• 2025-02-06 08:58:42.698214706 +0000 UTC m=+348594.230626689: ☑️ agreed by tangenta.

[codecov]

Codecov Report

Attention: Patch coverage is 91.66667% with 1 line in your changes missing coverage. Please review.

Please upload report for BASE (release-7.1@7f86db5). Learn more about missing BASE report.

Additional details and impacted files

@@               Coverage Diff                @@
##             release-7.1     #59263   +/-   ##
================================================
  Coverage               ?   73.4565%           
================================================
  Files                  ?       1213           
  Lines                  ?     382139           
  Branches               ?          0           
================================================
  Hits                   ?     280706           
  Misses                 ?      83489           
  Partials               ?      17944