chore: bump srt-slurm to v2.49.0

[cquil11]

Update inferencex-e2e/utils/srt-slurm from v2.47.2 (9d65c0ae) to v2.49.0 (7d983c79). The range adds the llm-d router frontend (NVIDIA/srt-slurm#588), a detailed_trace_annotation profiling knob (#589), and scrapes SGLang attention-DP followers for custom AIPerf metrics (#554).

[claude]

Looks good — straightforward submodule version bump.

What was reviewed: confirmed the diff is exactly a one-line gitlink update for inferencex-e2e/utils/srt-slurm (9d65c0a → 7d983c7), with no other files touched. No perf-changelog.yaml entry accompanies this bump, but checked recent entries and found no established pattern of adding one for pure submodule pointer bumps (as opposed to in-repo config/recipe changes), so this isn't flagged as a blocking gap.

Extended reasoning...

The only change is a Git submodule pointer bump (srt-slurm 9d65c0a → 7d983c7), with no other files in the InferenceX repo modified — no source, config, test, or docs content changed. No security-sensitive surface (auth, crypto, permissions) is touched. The submodule's own internal diff can't be inspected from this shallow, unchecked-out checkout, but mechanical version bumps of this kind are low-risk and match the PR description. No outstanding review comments or CHANGES_REQUESTED exist in the timeline, and the change is small and self-contained enough that a human need not block on it.