re-enable Azure Windows builds

[Anthchirp]

They will be horribly slow until we stop building cbflib

[codecov]

Codecov Report

Merging #1652 (760f29b) into main (396ba98) will increase coverage by 0.01%.
The diff coverage is 89.47%.

❗ Current head 760f29b differs from pull request most recent head 53d3ae7. Consider uploading reports for the commit 53d3ae7 to get more accurate results

@@            Coverage Diff             @@
##             main    #1652      +/-   ##
==========================================
+ Coverage   66.65%   66.66%   +0.01%     
==========================================
  Files         616      616              
  Lines       68983    69013      +30     
  Branches     9598     9603       +5     
==========================================
+ Hits        45981    46008      +27     
- Misses      21066    21069       +3     
  Partials     1936     1936              

[Anthchirp]

So the runtime is now on the same order of magnitude as linux and mac builds, so in principle this can be merged. Might want to look into that failing pickle test though. (Appreciate this is the aim of #1651)

[Anthchirp]

And we should probably document somewhere that Python 3.6 is not supported on Windows

[dagewa]

Sounds good. I'm happy to write a "Building DIALS on Windows" webpage. I suppose we are still some way off providing installable builds.

We should also clearly document that Windows support is still limited, due to lack of multiprocessing. That's something I want to look into, but I think it's going to be a case of making everything I look at pickleable, which is going to be quite some work.

[Anthchirp]

To be honest we can document the lack of support in the code quite easily...