** Work in progress **

Progress on iree-org/iree-test-suites#2.

I'm moving the tests at tests/e2e/matmul to the iree-org/iree-test-suites repository in iree-org/iree-test-suites#13. This deletes them from this repo and adds back test coverage using some workflow changes.

TODO:

• Port conv and attention tests too (this deletes them without adding them back yet)
• Add CPU test job
• Add tests to other GPU test jobs
• Iterate on the CMake options, flags, helper scripts, etc. so developers can still use these tests with minimal changes to their local workflows (this sort of move exposes a lot of the accumulated cruft and some deeper changes are overdue)
• Add docs to https://iree.dev/developers/general/testing-guide/

ci-exactly: build_packages, test_amd_mi250