chore: remove earliest_possible_extend default in schema

[jonas-jonas]

Related issue(s)

Checklist

• I have read the contributing guidelines.
• I have referenced an issue containing the design document if my change
  introduces a new feature.
• I am following the
  contributing code guidelines.
• I have read the security policy.
• I confirm that this pull request does not address a security
  vulnerability. If this pull request addresses a security vulnerability, I
  confirm that I got the approval (please contact
  [email protected]) from the maintainers to push
  the changes.
• I have added tests that prove my fix is effective or that my feature
  works.
• I have added or changed the documentation.

Further Comments

[codecov]

Codecov Report

Merging #3464 (36c5fcf) into master (eaaf375) will not change coverage.
Report is 1 commits behind head on master.
The diff coverage is n/a.

❗ Current head 36c5fcf differs from pull request most recent head c4b17df. Consider uploading reports for the commit c4b17df to get more accurate results

@@           Coverage Diff           @@
##           master    #3464   +/-   ##
=======================================
  Coverage   78.23%   78.23%           
=======================================
  Files         339      339           
  Lines       22495    22495           
=======================================
  Hits        17598    17598           
- Misses       3584     3585    +1     
+ Partials     1313     1312    -1     

see 1 file with indirect coverage changes