Bump version action isn't working

[lewisjared]

Describe the bug

https://github.com/openscm/openscm-units/actions/runs/20323377145

Blocking new automated releases

[znichollscr]

Probably time to give it a bit of copier update attention..

[lewisjared]

But I just installed pdm haha...

Diff is quite big going from v0.4.1 -> v0.14.4, but mostly docs related and the migration from pdm to uv

[lewisjared]

I'll do a manual release first, before bringing in the copier updates