fix #313 modification of owl temporary file in save function

[sygout]

Description:

Type of change:

• Bug fix.
• New feature.
• Documentation update.

Checklist:

This checklist can be used as a help for the reviewer.

• Is the code easy to read and understand?
• Are comments for humans to read, not computers to disregard?
• Does a new feature has an accompanying new test (in the CI or unit testing schemes)?
• Has the documentation been updated as necessary?
• Does this close the issue?
• Is the change limited to the issue?
• Are errors handled for all outcomes?
• Does the new feature provide new restrictions on dependencies, and if so is this documented?

Comments:

the following code creates a problem on Windows:

with tempfile.NamedTemporaryFile(suffix=".owl") as handle:
   super().save(file=handle.name, format="rdfxml", **kwargs)
   graph = rdflib.Graph() 
   graph.parse(handle.name, format="xml") 
   graph.serialize(destination=filename, format=format)

It is related to an issue with tempfile library. The problem comes from reopening the temporary file. the first line create and open the file. so the modification simply create a file name located in the temporary folder and use that path for the successive operations.

[francescalb]

Can you please write a little documentation on this PR? Tick off the box for bug fix and write a few sentences on why.

[francescalb]

This is deprecated due to #315