plugin: populate PMIX_PROC_INFO_ARRAY

[garlick]

Problem: the latest ompi v5 work requires a newer openpmix, but flux-pmix fails with the newer openpmix, apparently because it doesn't populate the PMIX_PROC_INFO_ARRAY.

Take care of this, then bump the openpmix version used in CI.

[codecov[bot]]

Codecov Report

Merging #62 (b860c9e) into main (e0d7cac) will increase coverage by 0.56%. The diff coverage is 100.00%.

:exclamation: Current head b860c9e differs from pull request most recent head b31e387. Consider uploading reports for the commit b31e387 to get more accurate results

@@            Coverage Diff             @@
##             main      #62      +/-   ##
==========================================
+ Coverage   78.46%   79.03%   +0.56%     
==========================================
  Files          10       10              
  Lines        1189     1207      +18     
==========================================
+ Hits          933      954      +21     
+ Misses        256      253       -3     

Impacted Files	Coverage Δ
src/shell/plugins/maps.c	86.04% <ø> (-0.44%)	:arrow_down:
src/shell/plugins/infovec.c	93.75% <100.00%> (+2.61%)	:arrow_up:
src/shell/plugins/main.c	80.23% <100.00%> (+1.38%)	:arrow_up:

:mega: We’re building smart automated test selection to slash your CI/CD build times. Learn more

[garlick]

Hmm, the centos7 container seems to have an older flux-core in it without taskmaps, and the centos8 builder is failing with

2022-12-18T04:39:45.7920279Z #8 [4/7] RUN sudo yum -y update  && sudo yum -y install     libevent-devel     zlib-devel  && sudo yum clean all
2022-12-18T04:39:46.4600743Z #8 0.768 CentOS Linux 8 - AppStream                      182  B/s |  38  B     00:00    
2022-12-18T04:39:46.4601544Z #8 0.771 Error: Failed to download metadata for repo 'appstream': Cannot prepare internal mirrorlist: No URLs in mirrorlist
2022-12-18T04:39:46.4604542Z #8 ERROR: executor failed running [/bin/sh -c sudo yum -y update  && sudo yum -y install     libevent-devel     zlib-devel  && sudo yum 

[grondo]

Oh, shoot. We need to update to the el7/el8 builders since CentOS went bye-bye. I had that in progress somewhere.. sorry I never proposed a PR!

[grondo]

I went ahead and pushed a commit here to move docker images from centos7,8 to el7/el8

[garlick]

Thank you!

[garlick]

Now rebased on top of #66

[garlick]

Thanks!