Another pass to clean up old session APIs

[AdamGS]

Summary

Closes: #000

Testing

[codspeed-hq]

Merging this PR will not alter performance

⚠️ Unknown Walltime execution environment detected

Using the Walltime instrument on standard Hosted Runners will lead to inconsistent data.

For the most accurate results, we recommend using CodSpeed Macro Runners: bare-metal machines fine-tuned for performance measurement consistency.

✅ 1581 untouched benchmarks

---

_{Comparing adamg/session-new-api-pass (8cce41b) with develop (575db9c)}