2.6.0rc8

What's Changed

• Automate version upgrade and introduce dspy.__version__ by @hmoazam in #1985
• python interpreter refactor to sandbox by @arnavsinghvi11 in #1956
• Allow returning empty results when nothing is retrieved from DatabricksRM by @chenmoneygithub in #1995
• Add AlfWorld dataset and tutorial. Improve BootstrapFT. by @okhat in #1996

Full Changelog: 2.6.0rc6...2.6.0rc8