Fix output artifact annotations to accept underscore and dash names

[Tomcli]

/kind bug

the first name worked but the second name doesn't. We should make dash and underscore work for artifact name annotations as well.

What steps did you take and what happened:
receive_file_task = receive_file_op(
send_file_task.output,
).add_pod_annotation(name='artifact_outputs', value=json.dumps(['saveartifact']))

receive_file_task = receive_file_op(
send_file_task.output,
).add_pod_annotation(name='artifact_outputs', value=json.dumps(['save-artifact']))

What did you expect to happen:

Additional information:
[Miscellaneous information that will assist in solving the issue.]

Environment:

• Python Version (use python --version):
• SDK Version:
• Tekton Version (use tkn version):
• Kubernetes Version (use kubectl version):
• OS (e.g. from /etc/os-release):