Fix a bunch of other low-hanging style lints (#36498)

- **Fix a bunch of low hanging style lints like unnecessary-return**
- **Fix single worktree violation**
- **And the rest**

Release Notes:

- N/A

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

@@ -311,9 +311,8 @@ unsafe fn parse_keystroke(native_event: id) -> Keystroke {
         let mut shift = modifiers.contains(NSEventModifierFlags::NSShiftKeyMask);
         let command = modifiers.contains(NSEventModifierFlags::NSCommandKeyMask);
         let function = modifiers.contains(NSEventModifierFlags::NSFunctionKeyMask)
-            && first_char.map_or(true, |ch| {
-                !(NSUpArrowFunctionKey..=NSModeSwitchFunctionKey).contains(&ch)
-            });
+            && first_char
+                .is_none_or(|ch| !(NSUpArrowFunctionKey..=NSModeSwitchFunctionKey).contains(&ch));
 
         #[allow(non_upper_case_globals)]
         let key = match first_char {

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

@@ -797,7 +797,7 @@ impl Platform for MacPlatform {
                                         .to_owned();
                                         result.set_file_name(&new_filename);
                                     }
-                                    return result;
+                                    result
                                 })
                             }
                         }

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

@@ -319,7 +319,7 @@ impl MacTextSystemState {
     fn is_emoji(&self, font_id: FontId) -> bool {
         self.postscript_names_by_font_id
             .get(&font_id)
-            .map_or(false, |postscript_name| {
+            .is_some_and(|postscript_name| {
                 postscript_name == "AppleColorEmoji" || postscript_name == ".AppleColorEmojiUI"
             })
     }

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

@@ -653,7 +653,7 @@ impl MacWindow {
                     .and_then(|titlebar| titlebar.traffic_light_position),
                 transparent_titlebar: titlebar
                     .as_ref()
-                    .map_or(true, |titlebar| titlebar.appears_transparent),
+                    .is_none_or(|titlebar| titlebar.appears_transparent),
                 previous_modifiers_changed_event: None,
                 keystroke_for_do_command: None,
                 do_command_handled: None,
@@ -688,7 +688,7 @@ impl MacWindow {
                 });
             }
 
-            if titlebar.map_or(true, |titlebar| titlebar.appears_transparent) {
+            if titlebar.is_none_or(|titlebar| titlebar.appears_transparent) {
                 native_window.setTitlebarAppearsTransparent_(YES);
                 native_window.setTitleVisibility_(NSWindowTitleVisibility::NSWindowTitleHidden);
             }