2.9.0

Highlights

• #1760: Exclude tasks based on serverless status
• #1750 (Breaking): Inject build_flavor in track templates

Enhancements

• #1756: Retrieve serverless build hash from nodes info API
• #1755: Add blob-store-stats telemetry device and tests
• #1743: Bulk action refresh param

Bug Fixes

• #1763: Fix running tracks across multiple load driver machines
• #1747: Fix rally-annotations index creation

Doc Changes

• #1748: Document actor system

Miscellaneous Changes

• #1759: Ensure serverless.mode/operator are always set