Further tweak the "Build Active Architecture Only" setting

Apply the setting at the project level instead of the target level, and
change debug builds to only build the active architecture.

Author: blast007

Xcode/BZFlag.xcodeproj/project.pbxproj

@@ -6961,7 +6961,7 @@
 					/opt/homebrew/lib,
 				);
 				MACOSX_DEPLOYMENT_TARGET = 10.13;
-				ONLY_ACTIVE_ARCH = YES;
+				ONLY_ACTIVE_ARCH = NO;
 			};
 			name = Release;
 		};
@@ -6986,7 +6986,6 @@
 			buildSettings = {
 				ENABLE_HARDENED_RUNTIME = YES;
 				INFOPLIST_FILE = "$(SRCROOT)/BZFlag-Info.plist";
-				ONLY_ACTIVE_ARCH = NO;
 				OTHER_LDFLAGS = (
 					"-lSDL2",
 					"-lGLEW",
@@ -7003,7 +7002,6 @@
 			buildSettings = {
 				ENABLE_HARDENED_RUNTIME = YES;
 				INFOPLIST_FILE = "$(SRCROOT)/BZFlag-Info.plist";
-				ONLY_ACTIVE_ARCH = NO;
 				OTHER_LDFLAGS = (
 					"-lSDL2",
 					"-lGLEW",