build-unit-test-docker: switch to ubuntu:lunar

Besides the usual changes, upgrade requires the following:

- remove liburing2-dbgsym - package no longer exists
- pip3 add `--break-system-packages` - pip3 will no longer install
  content at the system level without this.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Ic84e19c7c0f0e3be0057126d562b4aab00392aaf
1 file changed