Connector builder server: Build does not fail on failing unit tests

[flash1293]

The gradle task running the connector builder server unit tests does complete successfully even if the tests fail.

Run airbyte-connector-builder-server:airbytePythonDockerApply

The tests will run and log:

=================== 8 failed, 21 passed, 4 warnings in 2.75s ===================
============================= test session starts ==============================
platform linux -- Python 3.9.15, pytest-6.2.5, py-1.11.0, pluggy-1.0.0
rootdir: /home/integration_tests, configfile: ../pytest.ini
plugins: cov-4.0.0, requests-mock-1.10.0, anyio-3.6.2, mock-3.10.0, recording-0.12.1
collected 1 item

integration_tests/test_integration_test.py::test_test PASSED             [100%]

============================== 1 passed in 0.04s ===============================

Deprecated Gradle features were used in this build, making it incompatible with Gradle 8.0.

You can use '--warning-mode all' to show the individual deprecation warnings and determine if they come from your own scripts or plugins.

See https://docs.gradle.org/7.6/userguide/command_line_interface.html#sec:command_line_warnings

BUILD SUCCESSFUL in 24s

This probably happens because the run_tests.sh script doesn't fail along with a non-0 exit code of a command:

airbyte/airbyte-connector-builder-server/run_tests.sh

Lines 1 to 2 in 684fbff

	cd $1