Remove deprecated DataModule.dims usage in tests

[carmocca]

What does this PR do?

Part of #9939

Does your PR introduce any breaking changes? If yes, please list them.

None

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[codecov]

Codecov Report

Merging #9948 (5b00fec) into master (6429de8) will increase coverage by 4%.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master   #9948    +/-   ##
=======================================
+ Coverage      89%     93%    +4%     
=======================================
  Files         179     179            
  Lines       15831   15831            
=======================================
+ Hits        14053   14672   +619     
+ Misses       1778    1159   -619     

[tchaton]

LGTM !