libffmpeg: fix duplicated ffjni #459

Job	Run time
Android (lite)	6m 48s
Android (lite-lto)	10m 55s
LAVFilters	0s
Apple (default, macOS)	7m 2s
Apple (lite, macOS)	4m 1s
Apple (lite, iOS)	3m 0s
Linux_clang (default)	12m 16s
Apple (lite, visionOS)	2m 25s
Linux_clang (lite)	6m 41s
MinGW_GCC (lite)	6m 30s
Apple (lite, visionOSSimulator)	3m 5s
Linux_clang (lite-lto)	16m 29s
Apple (lite, tvOS)	2m 21s
Apple (lite-lto, macOS)	7m 30s
Apple (lite-lto, iOS)	3m 51s
RaspberryPiLegacy_clang	0s
Apple (lite-lto, iOSSimulator)	6m 36s
VCRT120_clang (lite)	7m 32s
Apple (lite-lto, tvOS)	3m 36s
Apple (lite-lto, tvOSSimulator)	5m 53s
Apple (lite-lto, macCatalyst)	5m 6s
VS2022 (default, windows-desktop)	32m 32s
VS2022LTL (lite, windows-desktop)	15m 30s
VS2022 (lite, windows-desktop)	19m 23s
VS2022LTL (default, windows-desktop)	24m 10s
VS2022 (lite, uwp)	13m 10s
Wasm	0s
Windows_clang (lite, windows-desktop)	9m 31s
Upload	35s
	3h 56m 28s

Provide feedback