Improve font rendering on macOS (#37622)

Part of https://github.com/zed-industries/zed/issues/7992

Release Notes:

- N/A

crates/gpui/src/platform/mac/text_system.rs

@@ -16,7 +16,7 @@ use core_foundation::{
 use core_graphics::{
     base::{CGGlyph, kCGImageAlphaPremultipliedLast},
     color_space::CGColorSpace,
-    context::CGContext,
+    context::{CGContext, CGTextDrawingMode},
     display::CGPoint,
 };
 use core_text::{
@@ -396,6 +396,12 @@ impl MacTextSystemState {
             let subpixel_shift = params
                 .subpixel_variant
                 .map(|v| v as f32 / SUBPIXEL_VARIANTS as f32);
+            cx.set_allows_font_smoothing(true);
+            cx.set_should_smooth_fonts(true);
+            cx.set_text_drawing_mode(CGTextDrawingMode::CGTextFill);
+            cx.set_gray_fill_color(0.0, 1.0);
+            cx.set_allows_antialiasing(true);
+            cx.set_should_antialias(true);
             cx.set_allows_font_subpixel_positioning(true);
             cx.set_should_subpixel_position_fonts(true);
             cx.set_allows_font_subpixel_quantization(false);