feat: update ConvMixer to support reactant #257

Job	Run time
downgrade	1h 13m 8s
test (1, ubuntu-latest, conv, default, true)	30m 9s
test (1, ubuntu-latest, dense, default, true)	19m 8s
test (1, ubuntu-latest, normalization, default, true)	1h 12m 50s
test (1, ubuntu-latest, misc, default, true)	37m 19s
test (1, ubuntu-latest, dense, default, false)	16m 19s
test (1, ubuntu-latest, misc, default, false)	31m 52s
test (1, macos-latest, all, default, true)	5h 9m 10s
test (1, windows-latest, all, default, true)	1h 50m 47s
	11h 40m 42s

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