[Chapel Merge] Fix indexing bug in system libfabric chplenv

Branch: refs/heads/main
Revision: 793fb4a
Author: ronawho
Link: Unavailable
Log Message:

Merge pull request #19015 from ronawho/fix-system-libfabric-chplenv

Fix indexing bug in system libfabric chplenv

[reviewed by @mppf]

The old code was trying to index into a tuple with () instead of [],
which doesn't work in python (but does in chapel) so update to use [].
Follow on to #18880.

Modified Files:
M util/chplenv/chpl_libfabric.py

Compare: https://github.com/chapel-lang/chapel/compare/9eca9e760013...793fb4a5e558