Fix extracting over symlinks with --dereference

Fix extracting over symlinks with --dereference

Extraction over symlink to a directory was broken in 75b03fdff4.
See https://savannah.gnu.org/bugs/index.php?68368

* src/tar.c (decode_options): Don't enable RESOLVE_BENEATH mode
if --dereference is given.
* tests/extrac33.at: New test.
* tests/Makefile.am: Add new test.
* tests/testsuite.at: Likewise.
* tests/extrac13.at: Add a keyword.
* tests/extrac31.at: Remove --absolute-names keyword: that option
is never used in the testcase. Add CVE-2025-45582 keyword instead.