### Summary

Add type hints to `ansible.parsing.dataloader::DataLoader`

### Issue Type

Feature Idea

### Component Name

lib/ansible/parsing/dataloader.py
self._basedir = '.'
        
        
        self._FILE_CACHE = dict()
        
        
        
        self._tempfiles = set()
        
        
        
        
        self._vaults = {}
        self._vault = VaultLib()
        self.set_vault_secrets(None)
    
    def set_vault_secrets(self, vault_secrets):