Revert "build: link to the system FontConfig by default on non-macOS systems"

This reverts commit 89f9dd7848.

src/build/Config.zig

@@ -424,19 +424,6 @@ pub fn init(b: *std.Build, appVersion: []const u8) !Config {
     // show up properly in `--help`.
 
     {
-        // These should default to `true` except on macOS because linking them
-        // to Ghostty statically when GTK is dynamically linked to them can
-        // cause crashes.
-        for (&[_][]const u8{
-            "fontconfig",
-        }) |dep| {
-            _ = b.systemIntegrationOption(
-                dep,
-                .{
-                    .default = if (target.result.os.tag.isDarwin()) false else true,
-                },
-            );
-        }
         // These dependencies we want to default false if we're on macOS.
         // On macOS we don't want to use system libraries because we
         // generally want a fat binary. This can be overridden with the
@@ -444,6 +431,7 @@ pub fn init(b: *std.Build, appVersion: []const u8) !Config {
         for (&[_][]const u8{
             "freetype",
             "harfbuzz",
+            "fontconfig",
             "libpng",
             "zlib",
             "oniguruma",