Fix the unit test on macOS

SDWebImage/Core/SDImageCoderHelper.m

@@ -290,9 +290,6 @@ static const CGFloat kDestSeemOverlap = 2.0f;   // the numbers of pixels to over
 }
 
 + (CGColorSpaceRef)colorSpaceGetDeviceRGB {
-    static CGColorSpaceRef colorSpace;
-    static dispatch_once_t onceToken;
-    dispatch_once(&onceToken, ^{
 #if SD_MAC
     NSScreen *mainScreen = nil;
     if (@available(macOS 10.12, *)) {
@@ -300,12 +297,16 @@ static const CGFloat kDestSeemOverlap = 2.0f;   // the numbers of pixels to over
     } else {
         mainScreen = [NSScreen screens].firstObject;
     }
-        colorSpace = mainScreen.colorSpace.CGColorSpace;
+    CGColorSpaceRef colorSpace = mainScreen.colorSpace.CGColorSpace;
+    return colorSpace;
 #else
+    static CGColorSpaceRef colorSpace;
+    static dispatch_once_t onceToken;
+    dispatch_once(&onceToken, ^{
         colorSpace = CGColorSpaceCreateWithName(kCGColorSpaceSRGB);
-#endif
     });
     return colorSpace;
+#endif
 }
 
 + (SDImagePixelFormat)preferredPixelFormat:(BOOL)containsAlpha {

Tests/Tests/SDImageCoderTests.m

@@ -217,7 +217,7 @@
 - (void)test14ThatHEIFWorks {
     if (@available(iOS 11, tvOS 11, macOS 10.13, *)) {
         NSURL *heifURL = [[NSBundle bundleForClass:[self class]] URLForResource:@"TestImage" withExtension:@"heif"];
-        BOOL supportsEncoding = !SDTestCase.isCI; // GitHub Action Mac env currently does not support HEIC encoding
+        BOOL supportsEncoding = NO; // public.heif UTI alwsays return false, use public.heic
         [self verifyCoder:[SDImageIOCoder sharedCoder]
         withLocalImageURL:heifURL
          supportsEncoding:supportsEncoding