Span: Fix typo inspan_CONFIG_SELECT_SPAN

Fixes liblcf build when targetting C++20 or newer

Author: Ghabry

src/lcf/span.h

@@ -20,7 +20,7 @@
 #define span_FEATURE_WITH_CONTAINER 1
 #define span_FEATURE_CONSTRUCTION_FROM_STDARRAY_ELEMENT_TYPE 1
 #define span_FEATURE_MAKE_SPAN 1
-#define span_CONFIG_SLECT_SPAN span_SPAN_NONSTD
+#define span_CONFIG_SELECT_SPAN span_SPAN_NONSTD
 #include <lcf/third_party/span.h>
 
 namespace lcf {