store/copr: fix missting Request.TxnScope (#43367)

[ti-chi-bot]

This is an automated cherry-pick of #43367

Ref #43481

What problem does this PR solve?

Issue Number: close #43365

Problem Summary:

What is changed and how it works?

Fix missing Request.TxnScope so the global stale-read optimization will take effect.

Seems there is no place to add a test for handling request inside coprocessor, the code change is really simple and safe.

Check List

Tests

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

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.

store/copr: fix missing `Request.TxnScope` so the global stale-read optimization will take effect.

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• cfzjywxk
• hawkingrei

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[cfzjywxk]

/merge

[ti-chi-bot]

This pull request has been accepted and is ready to merge.

Commit hash: 9d3b66a