python bindings: get version from package.xml

Requires gz-cmake4 4.1.0.

Signed-off-by: Steve Peters <[email protected]>

python/CMakeLists.txt

@@ -1,9 +1,10 @@
 # Detect if we are doing a standalone build of the bindings, using an external sdformat
 if(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
   cmake_minimum_required(VERSION 3.22.1)
-  set(SDF_VER 15)
-  project(sdformat${SDF_VER}-python VERSION ${SDF_VER})
-  find_package(sdformat${SDF_VER} REQUIRED)
+  find_package(gz-cmake4 4.1.0 REQUIRED)
+  gz_get_package_xml_version(${CMAKE_SOURCE_DIR}/../package.xml PACKAGE_XML)
+  project(sdformat${PACKAGE_XML_VERSION_MAJOR}-python VERSION ${PACKAGE_XML_VERSION})
+  find_package(sdformat${PROJECT_VERSION_MAJOR} REQUIRED)
   set(PROJECT_LIBRARY_TARGET_NAME "sdformat${PROJECT_VERSION_MAJOR}::sdformat${PROJECT_VERSION_MAJOR}")
   # require python dependencies to be found
   find_package(Python3 COMPONENTS Interpreter Development REQUIRED)