autotest: improve diagnostics around log download #36303

Job	Run time
build (stm32f7, chibios, 10)	3m 44s
build (stm32h7, chibios, 10)	3m 21s
build (fmuv2-plane, chibios, 10)	2m 7s
build (periph-build, chibios, 10)	3m 51s
build (iofirmware, chibios, 10)	1m 22s
build (CubeOrange-bootloader, chibios, 10)	1m 5s
build (fmuv3-bootloader, chibios, 10)	46s
build (revo-bootloader, chibios, 10)	56s
build (stm32h7-debug, chibios, 10)	2m 4s
build (fmuv3, chibios, 10)	5m 4s
build (revo-mini, chibios, 10)	3m 53s
build (MatekF405-Wing, chibios, 10)	4m 35s
build (CubeOrange-ODID, chibios, 10)	2m 30s
build (CubeRedPrimary-bootloader, chibios, 10)	48s
build (configure-all, chibios, 10)	9m 12s
build (build-options-defaults-test, chibios, 10)	6m 6s
build (signing, chibios, 10)	2m 54s
build (CubeOrange-PPP, chibios, 10)	2m 23s
build (CubeOrange-SOHW, chibios, 10)	2m 20s
build (Pixhawk6X-PPPGW, chibios, 10)	1m 10s
	1h 0m 11s

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