scripts/flaky_tests.py: Improve flaky tests detection (#5094)

## Problem

We still need to rerun some builds manually because flaky tests weren't
detected automatically.
I found two reasons for it:
- If a test is flaky on a particular build type, on a particular
Postgres version, there's a high chance that this test is flaky on all
configurations, but we don't automatically detect such cases.
- We detect flaky tests only on the main branch, which requires manual
retrigger runs for freshly made flaky tests.
Both of them are fixed in the PR.

## Summary of changes
- Spread flakiness of a single test to all configurations
- Detect flaky tests in all branches (not only in the main)
- Look back only at  7 days of test history (instead of 10)

.github/actions/run-python-test-set/action.yml

@@ -145,7 +145,11 @@ runs:
 
         if [ "${RERUN_FLAKY}" == "true" ]; then
           mkdir -p $TEST_OUTPUT
-          poetry run ./scripts/flaky_tests.py "${TEST_RESULT_CONNSTR}" --days 10 --output "$TEST_OUTPUT/flaky.json"
+          poetry run ./scripts/flaky_tests.py "${TEST_RESULT_CONNSTR}" \
+                                              --days 7 \
+                                              --output "$TEST_OUTPUT/flaky.json" \
+                                              --pg-version "${DEFAULT_PG_VERSION}" \
+                                              --build-type "${BUILD_TYPE}"
 
           EXTRA_PARAMS="--flaky-tests-json $TEST_OUTPUT/flaky.json $EXTRA_PARAMS"
         fi