Delete run_tests (#1281)

The file is obsolete and `pytest` should be used directly.

run_tests

@@ -1,32 +0,0 @@
-#!/bin/sh
-check_redis_running() {
-    redis-cli echo "just checking" > /dev/null
-    return $?
-}
-
-# Quit early if Redis server isn't running
-if ! check_redis_running; then
-    echo "Redis not running." >&2
-    exit 2
-fi
-
-if command -v rg >/dev/null; then
-    safe_rg=rg
-else
-    # Fall back for systems that don't have rg installed
-    safe_rg=cat
-fi
-
-export RUN_SLOW_TESTS_TOO=1
-if [ "$1" = '-f' ]; then  # Poor man's argparse
-    unset RUN_SLOW_TESTS_TOO
-    shift 1
-fi
-
-# For use on build server, we need exit code to be representative of success/failure
-if [ "$1" = '-x' ]; then
-    shift 1
-    /usr/bin/env python -m pytest -v tests $@ 2>&1
-else
-    /usr/bin/env python -m pytest -v tests $@ 2>&1 | egrep -v '^test_' | $safe_rg
-fi