[runtime] Add async-backing support

[DidacSF]

Description

This PR adds async-backing capabilites to both bajun and ajuna runtimes. Following the details in this Guide

Type of changes

• build: Changes that affect the build system or external dependencies (eg, Cargo, Docker)
• ci: Changes to CI configuration
• docs: Changes to documentation only
• feat: Changes to add a new feature
• fix: Changes to fix a bug
• refactor: Changes that do not alter functionality
• style: Changes to format the code
• test: Changes to add missing tests or correct existing tests

Checklist

• Tests for the changes have been added
• Necessary documentation is added (if appropriate)
• Formatted with cargo fmt --all
• Linted with cargo clippy --all-features --all-targets
• Tested with cargo test --workspace --all-features --all-targets

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (8851aa4) 75.76% compared to head (0c958da) 75.76%.

Additional details and impacted files

@@           Coverage Diff            @@
##           develop     #359   +/-   ##
========================================
  Coverage    75.76%   75.76%           
========================================
  Files           33       33           
  Lines         3508     3508           
========================================
  Hits          2658     2658           
  Misses         850      850           

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