fix: fix and clean trainer driver #7330

Job	Run time
Run tests (nv14)	6m 27s
Run tests (t12)	4m 3s
Run tests (t16)	8m 59s
Run tests (t18)	6m 48s
Run tests (t8)	3m 57s
Run tests (tlite)	3m 1s
Run tests (t20)	3m 44s
Run tests (tx12)	3m 37s
Run tests (tx16s)	6m 40s
Run tests (x10)	8m 12s
Run tests (x12s)	8m 44s
Run tests (x7)	2m 55s
Run tests (x9d)	3m 14s
Run tests (x9dp)	3m 36s
Run tests (x9dp2019)	4m 23s
Run tests (x9e)	3m 2s
Run tests (x9lite)	3m 24s
Run tests (x9lites)	3m 48s
Run tests (xlite)	3m 31s
Run tests (xlites)	3m 5s
Run builds (nv14)	4m 12s
Run builds (t12)	2m 26s
Run builds (t16)	5m 35s
Run builds (t18)	4m 38s
Run builds (t8;zorro;commando8)	3m 50s
Run builds (tlite;tlitef4;tpro;tprov2;lr3pro)	5m 38s
Run builds (t20)	2m 24s
Run builds (tx12;tx12mk2;boxer)	3m 49s
Run builds (tx16s)	4m 25s
Run builds (x10;x10-access)	7m 21s
Run builds (x12s)	4m 11s
Run builds (x7;x7-access)	3m 21s
Run builds (x9d;x9dp;x9dp2019)	4m 45s
Run builds (x9e;x9e-hall)	3m 20s
Run builds (x9lite;x9lites)	2m 59s
Run builds (xlite;xlites)	2m 54s
	2h 40m 58s

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