fix(deps): update wandb to 0.29.0 on r0.7.0

[balasaajay]

Update the r0.7.0 release branch from wandb==0.27.2 to wandb==0.29.0 and regenerate uv.lock.

W&B 0.29.0 requires OpenTelemetry API >=1.43.0, which conflicts with the pinned Megatron-Core development extra's ~=1.33.1 constraint. Add a documented override and align the locked API, SDK, OTLP exporters, and protobuf definitions at 1.43.0, with the matching semantic conventions and Prometheus exporter at 0.64b0. No unrelated package versions change.

Validation passed:

• uv lock --check and git diff --check.
• ruff check . and ruff format --check . using locked Ruff 0.9.10.
• Python 3.12 isolated environment constrained to lockfile versions: uv pip check passed for all 51 installed packages.
• W&B offline initialization, configuration, metric definition/logging, summary, and clean shutdown.
• OpenTelemetry in-memory tracing/metrics and OTLP/Prometheus exporter imports.
• Locked multi-storage-client 0.50.0 telemetry counters, gauges, tracing, flush, and shutdown.

Full GPU and end-to-end suites were not run. Lockfile resolution ran in the locally available NVIDIA PyTorch 26.08 container.

Upstream compatibility changes include W&B Server >=0.65.0 and macOS >=13.