BUG: test_wrong_url tests should be skipped with "--skip-network"

[Apteryks]

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Reproducible Example

In a container which doesn't have networking facilities, run the test suite with:

pytest" -vv pandas --skip-slow --skip-network

Observe that the following tests fail:

pandas/tests/io/xml/test_xml.py::test_wrong_url[lxml]
pandas/tests/io/xml/test_xml.py::test_wrong_url[etree]

### Issue Description

The test_wrong_url apparently need to have network access, but aren't skipped by --skip-network.

### Expected Behavior

Given --skip-network was provided, the pandas/tests/io/xml/test_xml.py::test_wrong_url[lxml] and pandas/tests/io/xml/test_xml.py::test_wrong_url[etree] tests should have been skipped.

### Installed Versions

1.3.5