Fix cmd.run with cwd and runas on macOS

[cdalvaro]

What does this PR do?

When calling cmd.run with cwd in combination with runas the working directory was not set on macOS

SLS test recipe

test 1 - cmd.run as root:
  cmd.run:
    - name: pwd | grep '/Users/Carlos/Desktop'
    - cwd: /Users/Carlos/Desktop

test 2 - cmd.run as user:
  cmd.run:
    - name: pwd | grep '/Users/Carlos/Desktop'
    - cwd: /Users/Carlos/Desktop
    - runas: Carlos

test 3 - git.cloned (uses cmd.run):
  git.cloned:
    - name: https://github.com/robbyrussell/oh-my-zsh.git
    - target: /Users/Carlos/.oh-my-zsh
    - user: Carlos

test 4 - git.latest (uses cmd.run):
  git.latest:
    - name: https://github.com/bhilburn/powerlevel9k.git
    - target: /Users/Carlos/.oh-my-zsh/custom/themes/powerlevel9k
    - user: Carlos

What issues does this PR fix or reference?

#51008

Previous Behavior

local:
----------
          ID: test 1 - cmd.run as root
    Function: cmd.run
        Name: pwd | grep '/Users/Carlos/Desktop'
      Result: True
     Comment: Command "pwd | grep '/Users/Carlos/Desktop'" run
     Started: 14:25:37.286952
    Duration: 13.423 ms
     Changes:
              ----------
              pid:
                  21164
              retcode:
                  0
              stderr:
              stdout:
                  /Users/Carlos/Desktop
----------
          ID: test 2 - cmd.run as user
    Function: cmd.run
        Name: pwd | grep '/Users/Carlos/Desktop'
      Result: False
     Comment: Command "pwd | grep '/Users/Carlos/Desktop'" run
     Started: 14:25:37.300748
    Duration: 58.866 ms
     Changes:
              ----------
              pid:
                  21167
              retcode:
                  1
              stderr:
              stdout:
----------
          ID: test 3 - git.cloned (uses cmd.run)
    Function: git.cloned
        Name: https://github.com/robbyrussell/oh-my-zsh.git
      Result: False
     Comment: Command 'git status -z --porcelain' failed: fatal: not a git repository (or any of the parent directories): .git
     Started: 14:25:37.374095
    Duration: 59.353 ms
     Changes:
----------
          ID: test 4 - git.latest (uses cmd.run)
    Function: git.latest
        Name: https://github.com/bhilburn/powerlevel9k.git
      Result: False
     Comment: fatal: not a git repository (or any of the parent directories): .git
     Started: 14:25:37.433847
    Duration: 1953.688 ms
     Changes:

Summary for local
------------
Succeeded: 1 (changed=2)
Failed:    3
------------
Total states run:     4
Total run time:   2.085 s

New Behavior

local:
----------
          ID: test 1 - cmd.run as root
    Function: cmd.run
        Name: pwd | grep '/Users/Carlos/Desktop'
      Result: True
     Comment: Command "pwd | grep '/Users/Carlos/Desktop'" run
     Started: 14:27:03.927846
    Duration: 26.604 ms
     Changes:
              ----------
              pid:
                  21433
              retcode:
                  0
              stderr:
              stdout:
                  /Users/Carlos/Desktop
----------
          ID: test 2 - cmd.run as user
    Function: cmd.run
        Name: pwd | grep '/Users/Carlos/Desktop'
      Result: True
     Comment: Command "pwd | grep '/Users/Carlos/Desktop'" run
     Started: 14:27:03.954871
    Duration: 58.845 ms
     Changes:
              ----------
              pid:
                  21436
              retcode:
                  0
              stderr:
              stdout:
                  /Users/Carlos/Desktop
----------
          ID: test 3 - git.cloned (uses cmd.run)
    Function: git.cloned
        Name: https://github.com/robbyrussell/oh-my-zsh.git
      Result: True
     Comment: Repository already exists at /Users/Carlos/.oh-my-zsh
     Started: 14:27:04.028293
    Duration: 106.831 ms
     Changes:
----------
          ID: test 4 - git.latest (uses cmd.run)
    Function: git.latest
        Name: https://github.com/bhilburn/powerlevel9k.git
      Result: True
     Comment: Repository /Users/Carlos/.oh-my-zsh/custom/themes/powerlevel9k is up-to-date
     Started: 14:27:04.135623
    Duration: 4391.238 ms
     Changes:

Summary for local
------------
Succeeded: 4 (changed=2)
Failed:    0
------------
Total states run:     4
Total run time:   4.584 s

Tests written?

Yes

Commits signed with GPG?

Yes