scripts/ingest_perf_test_result.py: increase connection timeout

[bayandin]

Problem

Sometimes default connection timeout is not enough to connect to the DB with perf test results, an example.

Similar changes were made for similar scripts:

• For scripts/flaky_tests.py in scripts/flaky_tests.py: handle connection error #4096
• For scripts/ingest_regress_test_result.py in Store Allure tests statistics in database #2367 (from the very begginning)

Summary of changes

• Connection timeout increased to 30s for scripts/ingest_perf_test_result.py

Checklist before requesting a review

• I have performed a self-review of my code.
• If it is a core feature, I have added thorough tests.
• Do we need to implement analytics? if so did you add the relevant metrics to the dashboard?
• If this PR requires public announcement, mark it with /release-notes label and add several sentences in this section.

Checklist before merging

• Do not forget to reformat commit message to not include the above checklist

[github-actions]

976 tests run: 936 passed, 0 failed, 40 skipped (full report)

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_{The comment gets automatically updated with the latest test results
8f6f107 at 2023-05-24T12:04:07.583Z :recycle:}