Do not try to delete shellcheck on selfhosted runners

It is not installed there per default and also on SUGAR runners there is
no sudo available. So much about self hosted runners being compatible.

Author: SuperSandro2000

internal/ghworkflow/workflow_checks.go

@@ -29,10 +29,12 @@ func checksWorkflow(cfg core.Configuration) {
 
 	if cfg.ShellCheck.Enabled.UnwrapOr(true) {
 		// delete the pretty out of date installed version of shellcheck so that make install-shellcheck installs the current version
-		j.addStep(jobStep{
-			Name: "Delete pre-installed shellcheck",
-			Run:  "sudo rm -f $(which shellcheck)",
-		})
+		if !ghwCfg.IsSelfHostedRunner {
+			j.addStep(jobStep{
+				Name: "Delete pre-installed shellcheck",
+				Run:  "sudo rm -f $(which shellcheck)",
+			})
+		}
 		j.addStep(jobStep{
 			Name: "Run shellcheck",
 			Run:  "make run-shellcheck",