Always log errors in run_shell_cmd()

[maddenp-cu]

Synopsis

Prior to a recent revamp of uwtools.utils.processing.run_shell_cmd(), errors resulting from a failed shell command were always logged, even when quiet=True was specified. The revamp inadvertently (?) changed this, leading to behavior like

$ uw rocoto iterate --cycle 2026-08-17T12 --database rocoto.db --workflow rocoto.xml --task foo
[2026-08-17T17:57:22]     INFO Iterating workflow
$

when the rocoto system module is not loaded such that rocotorun is not available. The error is displayed only if the --verbose flag is specified:

$ uw rocoto iterate --cycle 2026-08-17T12 --database rocoto.db --workflow rocoto.xml --task foo --verbose
[2026-08-17T17:57:47]    DEBUG Command: uw rocoto iterate --cycle 2026-08-17T12 --database rocoto.db --workflow rocoto.xml --task foo --verbose
[2026-08-17T17:57:47]     INFO Iterating workflow
[2026-08-17T17:57:47]    DEBUG Running: rocotorun -d rocoto.db -w rocoto.xml
[2026-08-17T17:57:47]    DEBUG Output:
[2026-08-17T17:57:47]    DEBUG   /bin/sh: line 1: rocotorun: command not found
$

But users should not have to specify --verbose to see an error like this.

This PR updates run_shell_cmd() so that the error behavior above is now

$ uw rocoto iterate --cycle 2026-08-17T12 --database rocoto.db --workflow rocoto.xml --task foo
[2026-08-17T18:29:37]     INFO Iterating workflow
[2026-08-17T18:29:37]    ERROR Failed with status: 127
[2026-08-17T18:29:37]    ERROR Output:
[2026-08-17T18:29:37]    ERROR   /bin/sh: line 1: rocotorun: command not found
$

Type

• Bug fix (corrects a known issue)

Impact

• This is a non-breaking change (existing functionality continues to work as expected)

Checklist

• I have added myself and any co-authors to the PR's Assignees list.
• I have reviewed the documentation and have made any updates necessitated by this change.
• Where helpful, I have written comments in this PR's Files changed view to assist reviewers.