Fix lazygit's UI becoming unresponsive when a background fetch asks for a passphrase (#4586)

Fix a regression introduced with #4525.

This fixes the problem that background fetching makes lazygit hang when
the fetch request needs to prompt for a passphrase. For Mac users who
use the keychain to store their ssh passphrases, this can happen when
lazygit is running while the machine goes to sleep, because macOS looks
the keychain in that case.

pkg/commands/oscommands/cmd_obj.go

@@ -196,6 +196,7 @@ func (self *CmdObj) PromptOnCredentialRequest(task gocui.Task) *CmdObj {
 
 func (self *CmdObj) FailOnCredentialRequest() *CmdObj {
 	self.credentialStrategy = FAIL
+	self.usePty = true
 
 	return self
 }