autotest: remove pointless try/except in PayloadPlaceMission #39624

Job	Run time
build (stm32f7, chibios, 10)	3m 46s
build (stm32h7, chibios, 10)	3m 37s
build (fmuv2-plane, chibios, 10)	1m 54s
build (periph-build, chibios, 10)	3m 42s
build (iofirmware, chibios, 10)	1m 30s
build (CubeOrange-bootloader, chibios, 10)	47s
build (fmuv3-bootloader, chibios, 10)	47s
build (revo-bootloader, chibios, 10)	54s
build (stm32h7-debug, chibios, 10)	2m 31s
build (fmuv3, chibios, 10)	5m 24s
build (revo-mini, chibios, 10)	4m 12s
build (MatekF405-Wing, chibios, 10)	4m 36s
build (CubeOrange-ODID, chibios, 10)	2m 48s
build (CubeRedPrimary-bootloader, chibios, 10)	1m 2s
build (configure-all, chibios, 10)	10m 21s
build (build-options-defaults-test, chibios, 10)	7m 33s
build (signing, chibios, 10)	2m 52s
build (CubeOrange-PPP, chibios, 10)	2m 16s
build (SOHW, chibios, 10)	4m 9s
build (Pixhawk6X-PPPGW, chibios, 10)	1m 27s
build (new-check, chibios, 10)	4m 25s
	1h 10m 33s

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