BE flakes: vertica QP tests flake with "Execution canceled by operator" error

[calherries]

There are 3-6 vertica flakes a day in query processor tests recently, and the last 5 failures have all been for the same reason. It's a relatively recent phenomenon according to this question:

They're all happening on different tests.

Example run: https://github.com/metabase/metabase/actions/runs/8894307603/job/24422318435?pr=41882#step:5:1144
metabase.query-processor-test.breakout-test/binning-with-source-card-with-explicit-joins-test

Example run: https://github.com/metabase/metabase/actions/runs/8885414686/job/24396737646#step:5:1291
metabase.query-processor-test.filter-test/contains-case-sensitive-test-2

Example run:
https://github.com/metabase/metabase/actions/runs/8885258720/job/24396229317#step:5:1214
metabase.query-processor-test.filter-test/text-equals-nil-empty-string-test-2

The errors all look very similar to the one below, and all due to this error: "ERROR: Execution canceled by operator".

ERROR in metabase.query-processor-test.breakout-test/binning-with-source-card-with-explicit-joins-test (execute.clj:709)
Uncaught exception, not in assertion.

                       clojure.lang.ExceptionInfo: Error executing query: [Vertica][VJDBC](3322) ERROR: Execution canceled by operator
    driver: :vertica
    params: nil
       sql: ["-- Metabase"
             "SELECT"
             "  ("
             "    FLOOR(((\"source\".\"People__longitude\" - -180.0) / 20.0)) * 20.0"
             "  ) + -180.0 AS \"People__longitude\","
             "  COUNT(*) AS \"count\""
             "FROM"
             "  ("
             "    SELECT"
             "      \"public\".\"test_data_orders\".\"id\" AS \"id\","
             ...]
      type: :invalid-query
                   java.sql.SQLTransientException: [Vertica][VJDBC](3322) ERROR: Execution canceled by operator
     SQLState: "57014"
    errorCode: 3322
com.vertica.support.exceptions.TransientException: [Vertica][VJDBC](3322) ERROR: Execution canceled by operator
        columnNumber: -1
         customState: "57014"
           diagState: #object[com.vertica.support.exceptions.DiagState 0x7d44cdfc "DIAG_GENERAL_ERROR"]
    messageKeyOrText: "[Vertica][VJDBC](3322) ERROR: Execution canceled by operator"
           rowNumber: -1