Fixes to ansible roles (fwd port of #3478)

[ndokos]

• repo.name -> repo.tag

• assert that `pbench_repo_name' is defined (users have to define it in their inventory)

• use `latest' when installing packages and stop ansible-lint from complaining about it

These fixes are incorporated into the pbench.agent collection, v1.0.11, available from Galaxy.

PBENCH-1129

[dbutenhof]

Rebasing will pick up Webb's legacy test fix. 😆

[webbnh]

Rebasing will pick up Webb's legacy test fix. 😆

I'm not sure that that fix covers this problem. 😢

[ndokos]

So what do they keep in Area-52?

[webbnh]

"pbench-tool-meister-stop" failed to execute successfully (exit code: 124)

I believe that that is a timeout. I'm inclined to say that that is nondeterministic behavior resulting from environmental effects.