Automatic discovery of i18n resources

Excluding qqq.json any .json file under static/i18n is now considered to
be a i18n resource. This eliminates the need to update the
i18n_resources_list.txt file every time a new language json file is
added. Thus Translatewiki PRs will not require extra work.

static/i18n_resources_list.txt

@@ -1,2 +0,0 @@
-i18n/en.json
-i18n/hy.json

static/meson.build

@@ -24,17 +24,29 @@ lib_resources = custom_target('resources',
     depends: preprocessed_resources
 )
 
-i18n_resource_files = run_command(find_program('python3'),
-                    '-c',
-                    'import sys; f=open(sys.argv[1]); print(f.read())',
-                    files('i18n_resources_list.txt')
-                 ).stdout().strip().split('\n')
+i18n_resource_listing_script = '''import glob
+import os
+import sys
+qqq = sys.argv[1]
+d = os.path.dirname(qqq)
+r = glob.glob(d + "/*.json")
+r.remove(qqq)
+for f in r: print(f)
+'''
+
+i18n_resource_listing_cmd = [
+                                find_program('python3'),
+                                '-c',
+                                i18n_resource_listing_script,
+                                files('i18n/qqq.json')
+                            ]
+
+i18n_resource_files = run_command(i18n_resource_listing_cmd).stdout().strip().split('\n')
 
 i18n_resources = custom_target('i18n_resources',
-    input: 'i18n_resources_list.txt',
+    input: i18n_resource_files,
     output: ['libkiwix-i18n-resources.cpp'],
     command:[i18n_compiler,
              '--cxxfile', '@OUTPUT0@',
              '@INPUT@'],
-    depend_files: i18n_resource_files
 )