chore: remove no longer needed macOS SDK forward declarations (#19446)

shell/browser/mac/atom_application.h

@@ -10,29 +10,13 @@
 #import <LocalAuthentication/LocalAuthentication.h>
 
 // Forward Declare Appearance APIs
-@interface NSApplication (HighSierraSDK)
+@interface NSApplication (MojaveSDK)
 @property(copy, readonly)
     NSAppearance* effectiveAppearance API_AVAILABLE(macosx(10.14));
 @property(copy, readonly) NSAppearance* appearance API_AVAILABLE(macosx(10.14));
 - (void)setAppearance:(NSAppearance*)appearance API_AVAILABLE(macosx(10.14));
 @end
 
-#if !defined(MAC_OS_X_VERSION_10_13_2)
-
-// forward declare Touch ID APIs
-typedef NS_ENUM(NSInteger, LABiometryType) {
-  LABiometryTypeNone = 0,
-  LABiometryTypeFaceID = 1,
-  LABiometryTypeTouchID = 2,
-} API_AVAILABLE(macosx(10.13.2));
-
-@interface LAContext (HighSierraPointTwoSDK)
-@property(nonatomic, readonly)
-    LABiometryType biometryType API_AVAILABLE(macosx(10.13.2));
-@end
-
-#endif
-
 // forward declare Access APIs
 typedef NSString* AVMediaType NS_EXTENSIBLE_STRING_ENUM;
 
@@ -46,13 +30,6 @@ typedef NS_ENUM(NSInteger, AVAuthorizationStatusMac) {
   AVAuthorizationStatusAuthorizedMac = 3,
 };
 
-@interface NSMenuItem (HighSierraSDK)
-@property(atomic, readwrite)
-    BOOL allowsKeyEquivalentWhenHidden API_AVAILABLE(macosx(10.13));
-- (void)setAllowsKeyEquivalentWhenHidden:(BOOL)arg1
-    API_AVAILABLE(macosx(10.13));
-@end
-
 @interface AVCaptureDevice (MojaveSDK)
 + (void)requestAccessForMediaType:(AVMediaType)mediaType
                 completionHandler:(void (^)(BOOL granted))handler