CI: Pin docker image.
CI: Pin docker image.

The azure-pipeline test Linux_Python_38_32bit_full_with_asserts has
been failing after the release of the latest manylinux2010. Pin
the docker image to an earlier version to fix this.

Closes #18553.

numpy/numpy,mhvk/numpy,pdebuyl/numpy,seberg/numpy,pdebuyl/numpy,pdebuyl/numpy,simongibbons/numpy,jakirkham/numpy,seberg/numpy,mhvk/numpy,charris/numpy,simongibbons/numpy,numpy/numpy,mhvk/numpy,pbrod/numpy,mattip/numpy,jakirkham/numpy,mattip/numpy,endolith/numpy,seberg/numpy,anntzer/numpy,charris/numpy,rgommers/numpy,charris/numpy,pbrod/numpy,pdebuyl/numpy,numpy/numpy,seberg/numpy,endolith/numpy,rgommers/numpy,jakirkham/numpy,pbrod/numpy,mhvk/numpy,rgommers/numpy,mattip/numpy,rgommers/numpy,anntzer/numpy,simongibbons/numpy,charris/numpy,mattip/numpy,anntzer/numpy,endolith/numpy,anntzer/numpy,pbrod/numpy,simongibbons/numpy,jakirkham/numpy,numpy/numpy,endolith/numpy,simongibbons/numpy,pbrod/numpy,mhvk/numpy,jakirkham/numpy