Modify Workflows

[threeal]

This issue suggests to modify workflows as follows:

• Remove build-debian-nightly.yml and build-debian-stable.yml since Debian build is no longer in use for this project.
• Merge build-and-test-nightly.yml and build-and-test-stable.yml into a single ci.yaml workflow file.
• Use the latest version of ROS 2 Workspace Action in the CI workflow.