### Elasticsearch Version

main

### Installed Plugins

_No response_

### Java Version

_bundled_

### OS Version

MacOS

### Problem Description

When there are 2 or more concurrent `_update` requests issued, one of them may fail with `ResourceAlreadyExistsException` exception which is misleading.


### Steps to Reproduce

1. Spawn a number of `_update` requests at the same time
2. Look at the results of these requests
3. Observe `ResourceAlreadyExistsException` being thrown in the case of conflict

### Logs (if relevant)

_No response_
x-pack/plugin/transform/qa/single-node-tests/src/javaRestTest/java/org/elasticsearch/xpack/transform/integration/TransformUpdateIT.java
"field": "stars"
                    }
                  }
                }
              }
            }""", transformDest, REVIEWS_INDEX_NAME);
        createTransformRequest.setJsonEntity(config);
        Map<String, Object> createTransformResponse = entityAsMap(client().performRequest(createTransformRequest));
        assertThat(createTransformResponse.get("acknowledged"), equalTo(Boolean.TRUE));
        Map<String, Object> transformConfig = getTransformConfig(transformId, BASIC_AUTH_VALUE_TRANSFORM_ADMIN_2);
        
        assertThat(transformConfig.get("authorization"), equalTo(Map.of("roles", List.of("transform_admin", DATA_ACCESS_ROLE_2))));
        
        createTransformRequest_2.setJsonEntity(config);
        createTransformResponse = entityAsMap(client().performRequest(createTransformRequest_2));
        assertThat(createTransformResponse.get("acknowledged"), equalTo(Boolean.TRUE));
        
        deleteUser(TEST_ADMIN_USER_NAME_2);
        deleteDataAccessRole(DATA_ACCESS_ROLE_2);
        
        try {
            getTransformConfig(transformId, BASIC_AUTH_VALUE_TRANSFORM_ADMIN_2);
            fail("request should have failed");
        } catch (ResponseException e) {
            assertThat(e.getResponse().getStatusLine().getStatusCode(), equalTo(401));
        }
        
        transformConfig = getTransformConfig(transformId, BASIC_AUTH_VALUE_TRANSFORM_ADMIN_1);