Fix: Fix build error with MSVC in BLI_span_test

span.size() returns an uint, causing a signed/unsigned comparison
using 3u sidesteps the issue

tests/gtests/blenlib/BLI_span_test.cc

@@ -291,7 +291,7 @@ TEST(span, VoidPointerSpan)
   float b;
   double c;
 
-  auto func1 = [](Span<void *> span) { EXPECT_EQ(span.size(), 3); };
+  auto func1 = [](Span<void *> span) { EXPECT_EQ(span.size(), 3u); };
   func1({&a, &b, &c});
 }