copy the .proto files into one location before running concatenate

something about the protoc compiler (maybe just on Python 3.12?) doesn't
like multiple -P path arguments, and until that's fixed, it's easier to
just copy the files into one spot, which works fine

patch_board_config.cmake

@@ -8,13 +8,20 @@ function (patch_board_config)
 		set(VENV_BIN_DIR ${VENV}/bin)
 	endif()
 
+	set(PROTO_OUTPUT_DIR ${CMAKE_CURRENT_BINARY_DIR}/proto)
+
 	add_custom_target(
 		PatchBoardConfig ALL
 		DEPENDS ${PROJECT_NAME}
 		WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}
+		# something in the protobuf compiler doesn't like the multiple paths,
+		# so we'll copy all the .proto files into one location
+		COMMAND ${CMAKE_COMMAND} -E make_directory ${PROTO_OUTPUT_DIR}
+		COMMAND ${CMAKE_COMMAND} -E copy ${CMAKE_SOURCE_DIR}/lib/nanopb/generator/proto/nanopb.proto ${PROTO_OUTPUT_DIR}
+		COMMAND ${CMAKE_COMMAND} -E copy ${CMAKE_SOURCE_DIR}/proto/enums.proto ${PROTO_OUTPUT_DIR}
+		COMMAND ${CMAKE_COMMAND} -E copy ${CMAKE_SOURCE_DIR}/proto/config.proto ${PROTO_OUTPUT_DIR}
 		COMMAND ${VENV_BIN_DIR}/concatenate
-			-P ./proto
-			-P ./lib/nanopb/generator/proto
+			-P ${PROTO_OUTPUT_DIR}
 			./build/${PROJECT_NAME}_${CMAKE_PROJECT_VERSION}_${GP2040_BOARDCONFIG}.bin
 			--json-board-config-filename ./configs/${GP2040_BOARDCONFIG}/board-config.json
 			--backup