tests: use python3 to run http_api test to fix failed integration_tests (#5473)

[ti-chi-bot]

This is an automated cherry-pick of #5473

What problem does this PR solve?

Issue Number: close #5474

What is changed and how it works?

Our CI envs still default to python2 to run tests. http_api requires using requests which brings certifi. Actually certifi's recent releases doesn't support python2 any more.

Release note

None

[ti-chi-bot]

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[zhangyangyu]

/run-all-tests

[codecov-commenter]

Codecov Report

❗ No coverage uploaded for pull request base (release-5.3@c6fdb3b). Click here to learn what that means.
The diff coverage is n/a.

@@               Coverage Diff                @@
##             release-5.3      #5481   +/-   ##
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  Files                  ?        224           
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  Branches               ?          0           
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  Hits                   ?      13367           
  Misses                 ?       9166           
  Partials               ?       1347           

[hi-rustin]

/merge

[hi-rustin]

/merge

[ti-chi-bot]

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

Commit hash: e3dab22

[ti-chi-bot]

@ti-chi-bot: Your PR was out of date, I have automatically updated it for you.

At the same time I will also trigger all tests for you:

/run-all-tests

If the CI test fails, you just re-trigger the test that failed and the bot will merge the PR for you after the CI passes.

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[nongfushanquan]

/run-all-tests