release/1.9.0: Update .github/workflows/ubuntu-ci-x86_64-gnu.yaml from develop (cannot cherry-pick 58ab975)

[climbfuji]

Summary

This PR updates .github/workflows/ubuntu-ci-x86_64-gnu.yaml from develop using the following procedure, since we cannot cherry-pick 58ab975 (it was merged as part of a squashed merge):

 1002  git clone -b release/1.9.0 --recurse-submodules https://github.com/jcsda/spack-stack spst-fix-gnu-ci-rel190
 1003  cd spst-fix-gnu-ci-rel190
 1006  git diff origin/develop origin/release/1.9.0
 1007  git diff origin/develop origin/release/1.9.0 .github/workflows/
 1008  git checkout origin/develop -- .github/workflows/ubuntu-ci-x86_64-gnu.yaml
 1011  git status
 1012  git commit -m "Update .github/workflows/ubuntu-ci-x86_64-gnu.yaml from develop (cannot cherry-pick 58ab975)"
 1013  git checkout -b bugfix/rel190_gnuci
 1014  git remote add dom https://github.com/climbfuji/spack-stack
 1015  git push dom bugfix/rel190_gnuci

Testing

• CI

Applications affected

None

Systems affected

None

Dependencies

None

Issue(s) addressed

Failing CI tests for Ubuntu GNU, branch release/1.9.0.

Checklist

• This PR addresses one issue/problem/enhancement, or has a very good reason for not doing so.
• These changes have been tested on the affected systems and applications.
• All dependency PRs/issues have been resolved and this PR can be merged.