test cases/frameworks/13 yelp: Do not reuse sources files

Additionally reorder test.json for better readability

test cases/frameworks/13 yelp/help/C/index2.page

@@ -0,0 +1,8 @@
+<page xmlns="http://projectmallard.org/1.0/"
+      xmlns:its="http://www.w3.org/2005/11/its"
+      type="guide"
+      id="index2">
+  <title>
+        Hello!
+  </title>
+</page>

test cases/frameworks/13 yelp/help/C/index3.page

@@ -0,0 +1,8 @@
+<page xmlns="http://projectmallard.org/1.0/"
+      xmlns:its="http://www.w3.org/2005/11/its"
+      type="guide"
+      id="index3">
+  <title>
+        Hello!
+  </title>
+</page>

test cases/frameworks/13 yelp/help/meson.build

@@ -8,14 +8,14 @@ gnome.yelp('meson',
 )
 
 gnome.yelp('meson-symlink',
-   sources: 'index.page',
+   sources: 'index2.page',
    media: 'media/test.txt',
    symlink_media: true,
    languages: ['de', 'es'],
 )
 
 gnome.yelp('meson-linguas',
-   sources: 'index.page',
+   sources: 'index3.page',
    media: 'media/test.txt',
    symlink_media: false,
 )

test cases/frameworks/13 yelp/test.json

@@ -6,17 +6,17 @@
     {"type": "file", "file": "usr/share/help/es/meson/media/test.txt"},
     {"type": "file", "file": "usr/share/help/de/meson/index.page"},
     {"type": "file", "file": "usr/share/help/de/meson/media/test.txt"},
-    {"type": "file", "file": "usr/share/help/C/meson-symlink/index.page"},
+    {"type": "file", "file": "usr/share/help/C/meson-symlink/index2.page"},
     {"type": "file", "file": "usr/share/help/C/meson-symlink/media/test.txt"},
+    {"type": "file", "file": "usr/share/help/es/meson-symlink/index2.page"},
     {"type": "file", "file": "usr/share/help/es/meson-symlink/media/test.txt"},
-    {"type": "file", "file": "usr/share/help/es/meson-symlink/index.page"},
+    {"type": "file", "file": "usr/share/help/de/meson-symlink/index2.page"},
-    {"type": "file", "file": "usr/share/help/de/meson-symlink/index.page"},
     {"type": "file", "file": "usr/share/help/de/meson-symlink/media/test.txt"},
-    {"type": "file", "file": "usr/share/help/C/meson-linguas/index.page"},
+    {"type": "file", "file": "usr/share/help/C/meson-linguas/index3.page"},
     {"type": "file", "file": "usr/share/help/C/meson-linguas/media/test.txt"},
+    {"type": "file", "file": "usr/share/help/es/meson-linguas/index3.page"},
     {"type": "file", "file": "usr/share/help/es/meson-linguas/media/test.txt"},
-    {"type": "file", "file": "usr/share/help/es/meson-linguas/index.page"},
+    {"type": "file", "file": "usr/share/help/de/meson-linguas/index3.page"},
-    {"type": "file", "file": "usr/share/help/de/meson-linguas/index.page"},
     {"type": "file", "file": "usr/share/help/de/meson-linguas/media/test.txt"}
   ],
   "skip_on_jobname": ["azure", "cygwin", "macos", "msys2"]