ci: use Node 18 in Circle CI

[willdurand]

Fixes #2617

[willdurand]

Looks like it's working :)

[codecov]

Codecov Report

Base: 99.52% // Head: 99.52% // No change to project coverage 👍

Coverage data is based on head (4899253) compared to base (6356fa9).
Patch has no changes to coverable lines.

❗ Current head 4899253 differs from pull request most recent head 32d7e5a. Consider uploading reports for the commit 32d7e5a to get more accurate results

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #2618   +/-   ##
=======================================
  Coverage   99.52%   99.52%           
=======================================
  Files          32       32           
  Lines        1699     1699           
=======================================
  Hits         1691     1691           
  Misses          8        8           

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

☔ View full report at Codecov.
📢 Do you have feedback about the report comment? Let us know in this issue.