bpo-31028: Fix test_pydoc when run directly (#2864) (#2911)

* bpo-31028: Fix test_pydoc when run directly

Fix get_pydoc_link() of test_pydoc to fix "./python
Lib/test/test_pydoc.py": get the absolute path to __file__ to prevent
relative directories.

* Use realpath() instead of abspath()

(cherry picked from commit fd46561167af6cd697191dd7ebb8c2fef5ad6493)
1 file changed