font: use regular JB Mono with dedicated Symbol font

Fixes #7069

I'm not sure if this will have follow-on negative effects. In my day to
day usage everything looks fine but its hard to really know. I think our
best chance is to merge this and see what feedback we get. I know for
sure positively that it does two things:

  1. Fixes the small symbols noted in #7069.
  2. Makes our binary size smaller since we no longer have unnecessary
     symbols embedded in our stylized fonts.

src/font/SharedGridSet.zig

@@ -291,6 +291,15 @@ fn collection(
             load_options.faceOptions(),
         ) },
     );
+    _ = try c.add(
+        self.alloc,
+        .regular,
+        .{ .fallback_loaded = try Face.init(
+            self.font_lib,
+            font.embedded.symbols,
+            load_options.faceOptions(),
+        ) },
+    );
 
     // On macOS, always search for and add the Apple Emoji font
     // as our preferred emoji font for fallback. We do this in case

src/font/embedded.zig

@@ -6,12 +6,13 @@
 //! redistribution and include their license as necessary.
 
 /// Default fonts that we prefer for Ghostty.
-pub const regular = @embedFile("res/JetBrainsMonoNerdFont-Regular.ttf");
-pub const bold = @embedFile("res/JetBrainsMonoNerdFont-Bold.ttf");
-pub const italic = @embedFile("res/JetBrainsMonoNerdFont-Italic.ttf");
-pub const bold_italic = @embedFile("res/JetBrainsMonoNerdFont-BoldItalic.ttf");
+pub const regular = @embedFile("res/JetBrainsMono-Regular.ttf");
+pub const bold = @embedFile("res/JetBrainsMono-Bold.ttf");
+pub const italic = @embedFile("res/JetBrainsMono-Italic.ttf");
+pub const bold_italic = @embedFile("res/JetBrainsMono-BoldItalic.ttf");
 pub const emoji = @embedFile("res/NotoColorEmoji.ttf");
 pub const emoji_text = @embedFile("res/NotoEmoji-Regular.ttf");
+pub const symbols = @embedFile("res/SymbolsNerdFontMono-Regular.ttf");
 
 /// Fonts with general properties
 pub const arabic = @embedFile("res/KawkabMono-Regular.ttf");
@@ -24,7 +25,7 @@ pub const nerd_font = @embedFile("res/JetBrainsMonoNerdFont-Regular.ttf");
 pub const code_new_roman = @embedFile("res/CodeNewRoman-Regular.otf");
 pub const inconsolata = @embedFile("res/Inconsolata-Regular.ttf");
 pub const geist_mono = @embedFile("res/GeistMono-Regular.ttf");
-pub const jetbrains_mono = @embedFile("res/JetBrainsMonoNoNF-Regular.ttf");
+pub const jetbrains_mono = @embedFile("res/JetBrainsMono-Regular.ttf");
 pub const julia_mono = @embedFile("res/JuliaMono-Regular.ttf");
 
 /// Cozette is a unique font because it embeds some emoji characters