copr: fix copr cache panic when tidb_enable_collect_execution_info is off (#48340)

[ti-chi-bot]

This is an automated cherry-pick of #48340

What problem does this PR solve?

Issue Number: close #48212

Problem Summary:

Goroutine panic because of nil pointer dereference.

What is changed and how it works?

When coprocessor cache is hit, check the details before set execution info.

Because some internal tasks may lead to cache hit when tidb_enable_collect_execution_info is turned off, so this need to be checked.

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.

# shell1
tiup playground nightly --kv=3 --mode=tikv-slim
# shell2
export TIKV_PATH=127.0.0.1:2379
export TIDB_TEST_STORE_NAME=tikv
make integrationtest

• Before

It may panic like the log in #48212

• After

No panic

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.

None

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: Defined2014, wshwsh12

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• OWNERS [Defined2014,wshwsh12]

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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2023-11-13 05:45:56.606438147 +0000 UTC m=+4055154.193548287: ☑️ agreed by Defined2014.
• 2023-11-13 05:48:12.966150263 +0000 UTC m=+4055290.553260393: ☑️ agreed by wshwsh12.

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (release-7.5@6927b21). Click here to learn what that means.
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Additional details and impacted files

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