Replace GNU/Linux with Linux; Correct macOS case

Signed-off-by: Sol Fisher Romanoff <sol@solfisher.com>

help/org.tenacityaudio.Tenacity.metainfo.xml

@@ -9,7 +9,7 @@
     <developer_name>Tenacity Community</developer_name>
     <summary>Audio editor and recorder. Nothing more, nothing less.</summary>
     <description>
-        <p>Tenacity is an easy-to-use multi-track audio editor and recorder for Windows, MacOS, GNU/Linux and other operating systems.</p>
+        <p>Tenacity is an easy-to-use multi-track audio editor and recorder for Windows, macOS, Linux and other operating systems.</p>
         <p>It is based on the popular Audacity audio editor and is being developed by a wide, diverse group of volunteers. It ships with some additional features and respects your privacy.</p>
         <p>You can use Tenacity to:</p>
         <ul>

vcpkg.json

@@ -1,7 +1,7 @@
 {
   "name": "tenacity",
   "version": "0.10",
-  "description": "Tenacity is an easy-to-use, cross-platform multi-track audio editor/recorder for Windows, MacOS, GNU/Linux and other operating systems.",
+  "description": "Tenacity is an easy-to-use, cross-platform multi-track audio editor/recorder for Windows, macOS, Linux and other operating systems.",
   "homepage": "https://tenacityaudio.org/",
   "license": "GPL-2.0-or-later",
   "supports": "!uwp",