Add Linux searchable paths created by game-data-packager

With the changes in #22819, it seems reasonable to add a couple of
default searchable paths for Linux that are created by the
`game-data-packager` utility, available in Debian and its various
derivatives.

Signed-off-by: Mathias Gibbens <gibmat@debian.org>

src/openrct2/platform/Platform.Linux.cpp

@@ -335,12 +335,18 @@ namespace OpenRCT2::Platform
 
     std::vector<std::string_view> GetSearchablePathsRCT1()
     {
-        return {};
+        return {
+            // game-data-packager uses this path when installing game files
+            "/usr/share/games/roller-coaster-tycoon",
+        };
     }
 
     std::vector<std::string_view> GetSearchablePathsRCT2()
     {
-        return {};
+        return {
+            // game-data-packager uses this path when installing game files
+            "/usr/share/games/roller-coaster-tycoon2",
+        };
     }
 
 #    ifndef NO_TTF