[Inference API] Fix node local rate limit calculator tests for non-snapshot builds

[timgrein]

Fixes #121294

Sometimes tests are run with -Dbuild.snapshot=false, which means the tests are run on a non-snapshot build, which implies that feature flags are disabled. As we inject NoopNodeLocalRateLimitCalculator as implementation for InferenceServiceRateLimitCalculator, when inference_cluster_aware_rate_limiting_feature_flag is disabled we should skip InferenceServiceNodeLocalRateLimitCalculatorTests as these tests should only test the real implementation (which is injected if the feature flag is enabled).

[maxjakob]

LGTM as long as for Sometimes tests are run with -Dbuild.snapshot=false "sometimes" here means at least once during continuous integration.

[timgrein]

LGTM as long as for Sometimes tests are run with -Dbuild.snapshot=false "sometimes" here means at least once during continuous integration.

Citing the mute reasons I think they run often enough in several CIs. I don't know, whether this means at least once on every PR:

[main] 7 consecutive failures in step release-tests
[main] 4 consecutive failures in step checkpart2_release-tests
[main] 18 failures in class org.elasticsearch.xpack.inference.common.InferenceServiceNodeLocalRateLimitCalculatorTests (3.2% fail rate in 570 executions)
[main] 8 failures in step release-tests (72.7% fail rate in 11 executions)
[main] 10 failures in step checkpart2_release-tests (66.7% fail rate in 15 executions)
[main] 8 failures in pipeline elasticsearch-periodic (72.7% fail rate in 11 executions)
[main] 9 failures in pipeline elasticsearch-pull-request (4.4% fail rate in 205 executions)

[elasticsearchmachine]

Pinging @elastic/ml-core (Team:ML)

[jonathan-buttner]

TIL 👍

[elasticsearchmachine]

💔 Backport failed

Status	Branch	Result
❌	9.0	Commit could not be cherrypicked due to conflicts
❌	8.18	Commit could not be cherrypicked due to conflicts

You can use sqren/backport to manually backport by running backport --upstream elastic/elasticsearch --pr 121527

[timgrein]

💚 All backports created successfully

Status	Branch	Result
✅	8.x
✅	9.0
✅	8.18

Questions ?

Please refer to the Backport tool documentation