[BUG] State files using `svn.export` fails when running under `state.test`

Description
Executing a highstate using the test=True parameter or using state.test will fail with an exception when the svn.export module is used.
When run as a regular highstate without the test=True parameter, the state executes without errors.

Error

----------
          ID: script_export
    Function: svn.export
        Name: https://svn.example.com/repo/path/trunk/test.txt
      Result: False
     Comment: An exception occurred in this state: Traceback (most recent call last):
                File "/usr/lib/python3.6/site-packages/salt/state.py", line 2277, in call
                  *cdata["args"], **cdata["kwargs"]
                File "/usr/lib/python3.6/site-packages/salt/loader/lazy.py", line 149, in __call__
                  return self.loader.run(run_func, *args, **kwargs)
                File "/usr/lib/python3.6/site-packages/salt/loader/lazy.py", line 1228, in run
                  return self._last_context.run(self._run_as, _func_or_method, *args, **kwargs)
                File "/usr/lib/python3.6/site-packages/contextvars/__init__.py", line 38, in run
                  return callable(*args, **kwargs)
                File "/usr/lib/python3.6/site-packages/salt/loader/lazy.py", line 1243, in _run_as
                  return _func_or_method(*args, **kwargs)
                File "/usr/lib/python3.6/site-packages/salt/loader/lazy.py", line 1276, in wrapper
                  return f(*args, **kwargs)
                File "/usr/lib/python3.6/site-packages/salt/states/svn.py", line 271, in export
                  out = __salt__[svn_cmd](cwd, target, user, username, password, *opts)
                File "/usr/lib/python3.6/site-packages/salt/loader/context.py", line 78, in __getitem__
                  return self.value()[item]
                File "/usr/lib/python3.6/site-packages/salt/loader/lazy.py", line 336, in __getitem__
                  super().__getitem__(item)  # try to get the item from the dictionary
                File "/usr/lib/python3.6/site-packages/salt/utils/lazy.py", line 105, in __getitem__
                  raise KeyError(key)
              KeyError: 'svn.list'
     Started: 10:59:12.776222
    Duration: 46.759 ms
     Changes:

The underlying state file:

dns_script_dns-gen:
  svn.export:
    - name: "https://svn.example.com/repo/path/trunk/test.txt"
    - target: /tmp
    - force: true
    - trust: true
    - externals: false
    - username: {{ salt['pillar.get']("svn_credentials:username", None) }}
    - password: {{ salt['pillar.get']("svn_credentials:password", None) }}

Versions Report
Observed starting with 3005.

Start in salt/states/svn.py around the export function at line 271 and reproduce the provided state with state.test or test=True. Trace the svn.list lookup shown in the exception and verify that svn.export completes without an exception in test mode while preserving normal highstate behavior.