ci: properly handle cross/native cases

test cases/common/229 native prop/crossfile.ini

@@ -0,0 +1,3 @@
+[properties]
+astring = 'cross'
+anarray = ['one', 'two']

test cases/common/229 native prop/meson.build

@@ -1,13 +1,14 @@
 project('get prop')
 
 x = meson.get_external_property('astring')
-assert(x=='mystring', 'did not get native property string. did you use "meson setup --native-file native.txt"')
+ref = meson.is_cross_build() ? 'cross' : 'mystring'
+assert(x==ref, 'did not get native property string. did you use "meson setup --native-file native.txt"')
 
 x = meson.get_external_property('astring', native: true)
 assert(x=='mystring', 'did not get native property with native:true and non-cross build.')
 
 x = meson.get_external_property('astring', 'fallback', native: false)
-assert(x=='mystring', 'did not get get native property with native:false and non-cross build.')
+assert(x==ref, 'did not get get native property with native:false and non-cross build.')
 
 
 x = meson.get_external_property('notexist', 'fallback')