CLI-1405: LocalMachineHelperTest::testExecuteFromCmd failure

[danepowell]

Motivation

These tests fail frequently in CI, and only in PHP 8.3. No idea why... possibly a race condition, or i/o issues, or an issue caused by paratest.

Proposed changes

Run these tests in serial.

Alternatives considered

Testing steps

1. Follow the contribution guide to set up your development environment or download a pre-built acli.phar for this PR.
2. Clear the kernel cache to pick up new and changed commands: ./bin/acli ckc
3. (add specific steps for this pr)

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 92.24%. Comparing base (fa517ff) to head (ef19cfb).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff            @@
##               main    #1804   +/-   ##
=========================================
  Coverage     92.24%   92.24%           
  Complexity     1817     1817           
=========================================
  Files           121      121           
  Lines          6823     6823           
=========================================
  Hits           6294     6294           
  Misses          529      529           

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[github-actions]

Try the dev build for this PR: https://acquia-cli.s3.amazonaws.com/build/pr/1804/acli.phar

curl -OL https://acquia-cli.s3.amazonaws.com/build/pr/1804/acli.phar
chmod +x acli.phar