Stop counting Known Flakes in max-fails
I noticed today that known_flakes are being added to the max_fails count so we can't use this yet in mesa CI.
For example the job a618_egl added dEQP-EGL.functional.color_clears.multi_context.gles3.rgba8888_pbuffer
to max_fails even though it’s in the src/freedreno/ci/freedreno-a618-flakes.txt
This fix treats the known flakes exactly like the expected fails.
cc @gfxstrand @eric