skip inference_endpoints api integration test on MKI (elastic#183705)

## Summary

This test leaves trained model that fails follow-up UI test on
[MKI](https://buildkite.com/elastic/appex-qa-serverless-kibana-ftr-tests/builds/1719#018f8523-c241-46ad-b664-441e12947a7f)
for both Security/Search projects.

Before this test on MKI 


![image](https://github.com/elastic/kibana/assets/10977896/a6f2fcfa-fae5-42a5-ab60-3e516fb1baff)

After this test run

<img width="1727" alt="image"
src="https://github.com/elastic/kibana/assets/10977896/3df27be2-a316-434c-ba6a-466db1cd602f">


The best fix is to make sure that system is reset to the state before
the test (delete added trained model, saved objects if any)

It might cause random failures on Kibana CI as well, but skipping for
MKI only now.

x-pack/test_serverless/api_integration/test_suites/common/index_management/inference_endpoints.ts

@@ -19,6 +19,8 @@ export default function ({ getService }: FtrProviderContext) {
   const service = 'elser';
 
   describe('Inference endpoints', function () {
+    // test adds new trained model '.elser_model_2_linux-x86_64', but does not clean it. Follow up tests are affected
+    this.tags(['failsOnMKI']);
     before(async () => {
       log.debug(`Creating inference endpoint`);
       try {