test: define UNUSED macros only once #2330

Job	Run time
LuaJIT (Linux/ARM64) Debug GC64:ON CC:gcc	3m 1s
LuaJIT (macOS/ARM64) Debug GC64:ON CC:clang	24s
LuaJIT (Linux/ARM64) Release GC64:ON CC:gcc	2m 39s
LuaJIT (macOS/ARM64) Release GC64:ON CC:clang	26s
LuaJIT (Linux/x86_64) Debug GC64:ON CC:gcc	3m 39s
LuaJIT (Linux/x86_64) Debug GC64:ON CC:clang	3m 12s
LuaJIT (macOS/x86_64) Debug GC64:ON CC:clang	38s
LuaJIT (Linux/x86_64) Debug GC64:OFF CC:gcc	36s
LuaJIT (Linux/x86_64) Debug GC64:OFF CC:clang	47s
LuaJIT (Linux/x86_64) Release GC64:ON CC:gcc	2m 39s
LuaJIT (Linux/x86_64) Release GC64:ON CC:clang	2m 20s
LuaJIT (macOS/x86_64) Release GC64:ON CC:clang	31s
LuaJIT (Linux/x86_64) Release GC64:OFF CC:gcc	31s
LuaJIT (Linux/x86_64) Release GC64:OFF CC:clang	38s
Tarantool (Linux/ARM64) Debug GC64:ON / luajit-integration	9m 8s
Tarantool (Linux/ARM64) Release GC64:ON / luajit-integration	8m 4s
Tarantool (macOS/ARM64) Debug GC64:ON / luajit-integration	2m 6s
Tarantool (macOS/ARM64) Release GC64:ON / luajit-integration	2m 9s
Tarantool (Linux/x86_64) Debug GC64:OFF / luajit-integration	3m 2s
Tarantool (Linux/x86_64) Debug GC64:ON / luajit-integration	5m 55s
Tarantool (macOS/x86_64) Debug GC64:ON / luajit-integration	3m 7s
Tarantool (Linux/x86_64) Release GC64:OFF / luajit-integration	3m 47s
Tarantool (Linux/x86_64) Release GC64:ON / luajit-integration	5m 4s
Tarantool (macOS/x86_64) Release GC64:ON / luajit-integration	2m 27s
	1h 6m 50s

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