[Azure DevOps] Removed code marked as deprecated in the upstream Backstage project

[awanlin]

Hey, I just made a Pull Request!

Removed code marked as deprecated in the upstream Backstage project

:heavy_check_mark: Checklist

• [x] A changeset describing the change and affected packages. (more info)
• [ ] Tests for new functionality and regression tests for bug fixes
• [ ] Screenshots attached (for UI changes)
• [x] All your commits have a Signed-off-by line in the message. (more info)

[backstage-goalie[bot]]

Changed Packages

Package Name	Package Path	Changeset Bump	Current Version
backend	workspaces/azure-devops/packages/backend	none	v0.0.4
@backstage-community/plugin-azure-devops-backend	workspaces/azure-devops/plugins/azure-devops-backend	patch	v0.6.9

[BethGriggs]

May need a rebase

[awanlin]

Should be good to go @BethGriggs, would like to get this merged as I'll be doing the 1.30.x upgrade later this week.

[awanlin]

Hi @nickboldt, any chance you can give this a look over? Would really like to have this in place as I plan to do the 1.30.x version bump tomorrow.