Use python 3.12

[ocefpaf]

Should be a bit faster and the whole stack is upgradable now so... Why not?

[ocefpaf]

linkcheck is failing with:

(content/code_gallery/data_analysis_and_visualization_notebooks/2021-10-25-ERDDAP-interpolate: line 20008) broken    https://erddap.ioos.us/erddap/convert/interpolate.html - HTTPSConnectionPool(host='erddap.ioos.us', port=443): Max retries exceeded with url: /erddap/convert/interpolate.html (Caused by SSLError(SSLCertVerificationError(1, '[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: unable to get local issuer certificate (_ssl.c:1000)')))

Maybe it is a transient error. I'll retry it tomorrow. If not, we may have a certificate problem :-/

[ocefpaf]

I'll check the failing doc URL in another PR. This one should be ready to go.

[MathewBiddle]

Thanks!