Without this, the tracer will not be injected on MacOS, as we need the
runner to circumvent SIP.
Also add a test that tests the autobuild-action to exercise this code path.

Add the missing `$CODEQL_RUNNER` prefix to the autobuild command line.
This intermediate process works around System Integrity Protection,
allowing the tracer to start the C# extractor for the dotnet builds
within the autobuild process.

The test used to pass without this because the legacy CLR tracer bypassed SIP
while dotnet 5 was used on the Actions virtual environment.
Now that the virtual environment uses dotnet 6, the CLR tracer no longer works,
and we need to explicitly work around SIP.

This test will eventually be replaced by an internal integration test for the
equivalent functionality in the CLI. For now, this change makes the test
continue to pass.

Ensure that this succeeds even if the legacy CLR tracer is not enabled.
The combination of the regular tracer and the SIP workaround within Actions
should be sufficient for this to pass.

We do not need to prefix `$CODEQL_RUNNER` here on macOS to bypass SIP,
because we assume that the `init` step exported `DYLD_INSERT_LIBRARIES`
into the environment, which activates the Actions workaround for SIP.
See actions/runner#416.

This test workflow does not source the environment from the init step,
so we need to manually read in the variable.