Add jraph dependency for upcoming ogbg_molpcba example.

[ameya98]

Redoing #1470

What does this PR do?

Fixes build for ogbg_molpcba example.

Checklist

• This PR fixes a minor issue (e.g.: typo or small bug) or improves the docs (you can dismiss the other
  checks if that's the case).

[codecov-commenter]

Codecov Report

Merging #1485 (aaa8e18) into main (8611538) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main    #1485   +/-   ##
=======================================
  Coverage   82.46%   82.46%           
=======================================
  Files          65       65           
  Lines        5424     5424           
=======================================
  Hits         4473     4473           
  Misses        951      951           

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