simplify imports xla / TPU

[Borda]

What does this PR do?

Partial #4859

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Did you have fun?

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[tchaton]

LTGM !

[codecov]

Codecov Report

Merging #4872 (d3fb0ec) into master (11e73ce) will increase coverage by 0%.
The diff coverage is 100%.

@@          Coverage Diff           @@
##           master   #4872   +/-   ##
======================================
  Coverage      93%     93%           
======================================
  Files         118     118           
  Lines        8905    9004   +99     
======================================
+ Hits         8282    8376   +94     
- Misses        623     628    +5