Move mixin to core

[kaushikb11]

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Fixes #<issue_number>

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[codecov]

Codecov Report

Merging #8396 (e53b914) into master (000fbe6) will decrease coverage by 5%.
The diff coverage is 100%.

@@           Coverage Diff           @@
##           master   #8396    +/-   ##
=======================================
- Coverage      93%     88%    -5%     
=======================================
  Files         216     217     +1     
  Lines       14115   14116     +1     
=======================================
- Hits        13087   12423   -664     
- Misses       1028    1693   +665     

[Borda]

just curious, what is the motivation?

[kaushikb11]

@Borda Reference

[awaelchli]

doesn't the device_dtype_mixin require a rerouting of the imports for BC?

[kaushikb11]

doesn't the device_dtype_mixin require a rerouting of the imports for BC?

I don't think it would be required for internal use.

[justusschock]

@kaushikb11

I don't think it would be required for internal use.

Not for internal use, but it was part of the public API in utilities (I use it quite often in my own code) so I think we should reroute this together with a Deprecation Warning

[tchaton]

LGTM !