tests: remove extra_files.py (#12223)

The script I used is included as testsuite/driver/kill_extra_files.py,
though at this point it is for mostly historical interest.

Some of the tests in libraries/hpc relied on extra_files.py, so this
commit includes an update to that submodule.

One test in libraries/process also relies on extra_files.py, but we
cannot update that submodule so easily, so for now we special-case it
in the test driver.

1 files changed, 0 insertions, 0 deletions

diff --git a/libraries/hpc b/libraries/hpc
-Subproject 5caceac7a05741f87f970e1d3f572b1fd8f10ce
+Subproject b28546ca003c6dbff586609a093e8c8091c34b1