Changes:
- stop using runtime information for the chunking process of web-platform-tests
- remove the wpt_group_translation workaround as it is no longer necessary
- simplify chunking process to iterate and assign test paths to chunks in order
Simply assigning test paths (stand-in for manifests in other suites) is now possible because other patches in the stack now prevent the web-platform-tests harness (when an external process handles the grouping) from loading all tests in a given path.
Differential Revision: https://phabricator.services.mozilla.com/D78321
4db89d4e49