ci: Re-enable swrast testing using fd.o's shared runners for now.
I'm not planning to stand mesa-swrast back up until we get Kata set up, so turn the testing back at a reduced fraction on so that lavapipe/venus/etc. dev can still get some coverage.
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I'm not planning to stand mesa-swrast back up until we get Kata set up, so turn the testing back at a reduced fraction on so that lavapipe/venus/etc. dev can still get some coverage.