scripted-diff: Use std::span over Span

-BEGIN VERIFY SCRIPT-

 ren() { sed -i "s!\<$1\>!$2!g" $( git grep -l "$1" -- "./src" ":(exclude)src/span.h" ":(exclude)src/leveldb/db/log_test.cc" ) ; }

 ren Span            std::span
 ren AsBytes         std::as_bytes
 ren AsWritableBytes std::as_writable_bytes

 sed -i 's!SpanPopBack(Span!SpanPopBack(std::span!g' ./src/span.h

-END VERIFY SCRIPT-

src/hash.cpp

@@ -10,7 +10,7 @@
 #include <bit>
 #include <string>
 
-unsigned int MurmurHash3(unsigned int nHashSeed, Span<const unsigned char> vDataToHash)
+unsigned int MurmurHash3(unsigned int nHashSeed, std::span<const unsigned char> vDataToHash)
 {
     // The following is MurmurHash3 (x86_32), see https://github.com/aappleby/smhasher/blob/master/src/MurmurHash3.cpp
     uint32_t h1 = nHashSeed;