Fix JobStoreDocument validator

[utf]

I found that the validator in the JobStoreDocument introduced in #424 was causing atomate2 to stop working. I can't see why this validator is actually needed, it will just slow things down, so I removed it.

[codecov]

Codecov Report

Merging #478 (66296ea) into main (beb78b1) will decrease coverage by 0.01%.
Report is 4 commits behind head on main.
The diff coverage is 100.00%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #478      +/-   ##
==========================================
- Coverage   99.86%   99.86%   -0.01%     
==========================================
  Files          20       20              
  Lines        1516     1508       -8     
  Branches      419      415       -4     
==========================================
- Hits         1514     1506       -8     
  Misses          2        2              

Files	Coverage Δ
src/jobflow/core/job.py	100.00% <100.00%> (ø)
src/jobflow/core/schemas.py	100.00% <100.00%> (ø)
src/jobflow/core/store.py	100.00% <ø> (ø)