Update .npmignore once more to catch more files

This time I verified by making sure I could `npm pack` and then `npm install`, so hopefully this one carries more certainty than the last commit.

Author: savetheclocktower

.npmignore

@@ -18,6 +18,7 @@
 !vendor/pcre/10.44/src/*.h
 !vendor/pcre/10.44/src/*.c
 !vendor/pcre/10.44/src/sljit/*
+!vendor/pcre/10.44/src/sljit/allocator_src/*
 !vendor/pcre/10.44/COPYING
 !vendor/pcre/10.44/LICENSE