fix: remove --enforce from observability make target

[averevki]

Summary

The new make observability target fails some tests that could only run under testsuite configuration for standalone authorino (aka with --standalone flag). Removing --enforce flag from observability target so it is possible run it with either standard authorino or with standalone authorino by adding --standalone flag to the observability target.

ERROR testsuite/tests/singlecluster/authorino/metrics/test_deep_metrics.py::test_deep_metrics[authorization] - Failed: Unable to run Standalone only test: Standalone mode is disabled, please use --standalone flag
ERROR testsuite/tests/singlecluster/authorino/metrics/test_deep_metrics.py::test_deep_metrics[identity] - Failed: Unable to run Standalone only test: Standalone mode is disabled, please use --standalone flag
ERROR testsuite/tests/singlecluster/authorino/metrics/test_deep_metrics.py::test_deep_metrics[metadata] - Failed: Unable to run Standalone only test: Standalone mode is disabled, please use --standalone flag
ERROR testsuite/tests/singlecluster/authorino/metrics/test_deep_metrics.py::test_deep_metrics[response] - Failed: Unable to run Standalone only test: Standalone mode is disabled, please use --standalone flag
ERROR testsuite/tests/singlecluster/authorino/operator/tracing/test_tracing.py::test_tracing - Failed: Unable to run Standalone only test: Standalone mode is disabled, please use --standalone flag
ERROR testsuite/tests/singlecluster/authorino/operator/tracing/test_tracing_tags.py::test_tracing_tags - Failed: Unable to run Standalone only test: Standalone mode is disabled, please use --standalone flag

Verification steps

# run mark with the standard authorino and see how some metrics and tracing tests will be skipped instead of failed
flags=-vv make observability

# run only observability tests capable running with standalone authorino
flags="-vv --standalone" make observability

[silvi-t]

LGTM 👍

[crstrn13]

LGTM 👍

[emmaaroche]

LGTM 👍