Consolidate the labels in this repository

[StanFromIreland]

Describe the enhancement or feature you would like

I was going through and labeling old issues today, and it made me realize how duplicated and unnecessary some labels in this reposition are, for reference we have 37 labels (and only 96 issues!), the complete list. To start, some suggestions:

• CLA signed/CLA not signed these aren't used anymore, why do we still have them?
• duplicate closing the PR as a duplicate already provides this information (and more, since an issue can be specified), I see little benefit of the label.
• good first issue/help wanted/size-XS (0 uses) I think we should stick to one, almost all issues need help, and they are generally used for the same purpose, easy issues.
• hacktoberfest this label has no uses, I think we can remove it (note, we also have topic-sprints).
• project: triagers/topic-triage I think we can merge these, they only have a few issues each.
• python (0 uses)/guide-automation I think we can remove the unused label, it is superseded by the latter.

cc @ezio-melotti