[partition] Handle missing requirements by disabling the module

src/modules/partition/CMakeLists.txt

@@ -5,8 +5,13 @@ include(GenerateExportHeader)
 find_package( Qt5 REQUIRED DBus )
 find_package( KF5 REQUIRED Config CoreAddons I18n WidgetsAddons )
 
-find_package( KPMcore 3.3 REQUIRED )
+find_package( KPMcore 3.3 )
+set_package_properties(
+    KPMcore PROPERTIES
+    PURPOSE "For partitioning module"
+)
 
+if ( KPMcore_FOUND )
     include_directories( ${KPMCORE_INCLUDE_DIR} )
     include_directories( ${PROJECT_BINARY_DIR}/src/libcalamaresui )
 
@@ -66,3 +71,6 @@ calamares_add_plugin( partition
             KF5::CoreAddons
         SHARED_LIB
     )
+else()
+    calamares_skip_module( "partition (missing suitable KPMcore)" )
+endif()