Use more prevalent "socioeconomic" version instead of "socio-economic"

[yarikoptic]

Original motivation is from constantly running into this while detecting typos with codespell.
FTR, to codespell this "typo" was added within
codespell-project/codespell#3280 and here is "recent" discussion on likely allowing both forms: codespell-project/codespell#3353 but giving more arguments.

It is true that "socio-economic" is also known and generally considered correct. But if someone goes to
https://www.merriam-webster.com/dictionary/socio-economic it does list it as "socioeconomic" and examples follow the version without the dash. So it seems to be the prevalent version, and thus why not to use it instead?

.it and .ro might (or not) want to adopt too?

❯ git grep socio-economic  # filtered from non translated, repeated
content/version/1/4/code-of-conduct.ro.md:statut socio-economic, naționalitate, aspect fizic, rasă, religie, identitate sau orientare sexuală.
content/version/2/1/code_of_conduct.it.md:socio-economico, nazionalità, aspetto, razza, casta, colore della pelle,