Fix build.zig and use zig fmt (#4242)

+ `std.mem.split` is deprecated, `splitScalar` seems like the intended choice here
+ zig files should be formatted according to `zig fmt`

src/build.zig

@@ -59,7 +59,7 @@ fn compileRaylib(b: *std.Build, target: std.Build.ResolvedTarget, optimize: std.
         const content = try std.fs.cwd().readFileAlloc(b.allocator, file, std.math.maxInt(usize));
         defer b.allocator.free(content);
 
-        var lines = std.mem.split(u8, content, "\n");
+        var lines = std.mem.splitScalar(u8, content, '\n');
         while (lines.next()) |line| {
             if (!std.mem.containsAtLeast(u8, line, 1, "SUPPORT")) continue;
             if (std.mem.startsWith(u8, line, "//")) continue;
@@ -149,7 +149,6 @@ fn compileRaylib(b: *std.Build, target: std.Build.ResolvedTarget, optimize: std.
                 raylib.addLibraryPath(.{ .cwd_relative = "/usr/lib" });
                 raylib.addIncludePath(.{ .cwd_relative = "/usr/include" });
                 if (options.linux_display_backend == .X11 or options.linux_display_backend == .Both) {
-
                     raylib.defineCMacro("_GLFW_X11", null);
                     raylib.linkSystemLibrary("X11");
                 }