Python: Remove test with CRLF line endings

These were causing `git` to behave strangely, leaving files that were
impossible to reset. In the future we should probably generate these
problematic test files on the fly, so that they don't have to exist in
the repo, but in the short run, it's easier to just remove them so as to
not block other users of the repo.

Author: tausbn

python/ql/test/extractor-tests/line_endings/README.md

@@ -0,0 +1 @@
+The test files in this directory were causing some issues with `git`, due to the use of CRLF line endings. For this reason they have been temporarily removed. You can consult the commit history for when this file was added to see what they looked like.