Add 'void' to C function declarations

Author: dempseyatgithub

BuildSettingExtractor/BuildSettingExtractor.m

@@ -11,7 +11,7 @@
 #import "BuildSettingInfoSource.h"
 #import "Constants+Categories.h"
 
-static NSSet *XcodeCompatibilityVersionStringSet() {
+static NSSet *XcodeCompatibilityVersionStringSet(void) {
     static NSSet *_compatibilityVersionStringSet;
     static dispatch_once_t onceToken;
     dispatch_once(&onceToken, ^{

BuildSettingExtractor/Constants+Categories.m

@@ -159,7 +159,7 @@ + (NSError *)errorForSettingInfoFilesNotFound:(NSArray *)subpathErrorStrings {
 @end
 
 // Can remove once deployment target is macOS 11.3 or later
-NSString * TPSMultipleUnderlyingErrorsKey() {
+NSString * TPSMultipleUnderlyingErrorsKey(void) {
     if (@available(macOS 11.3, *)) {
         return NSMultipleUnderlyingErrorsKey;
     } else {