PHPStan: "\Drupal calls should be avoided in classes"

Problem/Motivation

PHPStan is reporting a number of errors due to \Drupal calls from classes.

I believe all PHPStan issues were fixed during the GitLabCI migration, and these lines seem to have been added before it, so it could be a change to the PHPStan rules in GitLabCI:

 ------ -------------------------------------------------------------------------------------------------------- 
  Line   modules/project_browser_source_example/src/Plugin/ProjectBrowserSource/ProjectBrowserSourceExample.php  
 ------ -------------------------------------------------------------------------------------------------------- 
  47     \Drupal calls should be avoided in classes, use dependency injection                                    
         instead                                                                                                 
 ------ -------------------------------------------------------------------------------------------------------- 
 ------ ---------------------------------------------------------------------- 
  Line   src/Commands/UpdateFixtureCommands.php                                
 ------ ---------------------------------------------------------------------- 
  87     \Drupal calls should be avoided in classes, use dependency injection  
         instead                                                               
 ------ ---------------------------------------------------------------------- 
 ------ ---------------------------------------------------------------------- 
  Line   src/Plugin/ProjectBrowserSource/DrupalCore.php                        
 ------ ---------------------------------------------------------------------- 
  180    \Drupal calls should be avoided in classes, use dependency injection  
         instead                                                               
 ------ ---------------------------------------------------------------------- 
 ------ ---------------------------------------------------------------------- 
  Line   src/Plugin/ProjectBrowserSource/MockDrupalDotOrg.php                  
 ------ ---------------------------------------------------------------------- 
  328    \Drupal calls should be avoided in classes, use dependency injection  
         instead                                                               
 ------ ---------------------------------------------------------------------- 
 ------ ---------------------------------------------------------------------- 
  Line   src/ProjectBrowserFixtureHelper.php                                   
 ------ ---------------------------------------------------------------------- 
  386    \Drupal calls should be avoided in classes, use dependency injection  
         instead                                                               
  521    \Drupal calls should be avoided in classes, use dependency injection  
         instead                                                               
 ------ ---------------------------------------------------------------------- 
 ------ ---------------------------------------------------------------------- 
  Line   tests/modules/project_browser_test/src/Datetime/TestTime.php          
 ------ ---------------------------------------------------------------------- 
  37     \Drupal calls should be avoided in classes, use dependency injection  
         instead                                                               
 ------ ---------------------------------------------------------------------- 
 ------ ---------------------------------------------------------------------- 
  Line   tests/modules/project_browser_test/src/DrupalOrgClientMiddleware.php  
 ------ ---------------------------------------------------------------------- 
  94     \Drupal calls should be avoided in classes, use dependency injection  
         instead                                                               
 ------ ---------------------------------------------------------------------- 
 [ERROR] Found 8 errors  

Steps to reproduce

Check a GitLabCI run of PHPStan, such as: https://git.drupalcode.org/issue/project_browser-3437721/-/jobs/1345914

Proposed resolution

Replace \Drupal calls with dependency injection.