psr/log causes errors on the Sage 11 theme

[Dyras]

Describe the bug:

I'm using Sage 11 on a Trellis site. Since psr/log (seemingly) isn't namespaced it collides with the pre-installed psr/log in the theme.

Steps to reproduce:

1. Set up a website with Sage 11, Acorn, Trellis. The entire Roots stack really
2. Try to pre-cache the site using "wp acorn optimize"
3. You get this error:

   Psr\Log\InvalidArgumentException 

  Level "\Monolog\Level::Debug" is not defined, use one of: 100, 200, 250, 300, 400, 500, 550, 600, DEBUG, INFO, NOTICE, WARNING, ERROR, CRITICAL, ALERT, EMERGENCY

  at public/content/plugins/google-listings-and-ads/vendor/monolog/monolog/src/Monolog/Logger.php:520
    516▕             throw new InvalidArgumentException('Level "'.$level.'" is not defined, use one of: '.implode(', ', array_keys(static::$levels) + static::$levels));
    517▕         }
    518▕ 
    519▕         if (!is_int($level)) {
  ➜ 520▕             throw new InvalidArgumentException('Level "'.var_export($level, true).'" is not defined, use one of: '.implode(', ', array_keys(static::$levels) + static::$levels));
    521▕         }
    522▕ 
    523▕         return $level;
    524▕     }

      +23 vendor frames 
  24  phar:///usr/bin/wp/php/boot-phar.php:20
  25  /usr/bin/wp:4

Expected behavior:

psr/log and everything else for that matter should be namespaced so that they don't collide with anything else.

Actual behavior:

They aren't which prevents some things from working using the Sage 11 theme and presumably also with other plugins that don't namespace psr/log

Additional details:

Info about the issue:
https://roots.io/acorn/docs/compatibility/

Similar issue with Cloudflare's plugin that they recently fixed:
cloudflare/Cloudflare-WordPress#554