[ruby/strscan] Bump version

If we use the same version as the default strscan gem in Ruby, "gem
install" doesn't extract .gem. It fails "gem install" because "gem
install" can't find ext/strscan/ to be built.

https://github.com/ruby/strscan/commit/3ceafa6cdc

ext/strscan/strscan.c

@@ -22,7 +22,7 @@ extern size_t onig_region_memsize(const struct re_registers *regs);
 
 #include <stdbool.h>
 
-#define STRSCAN_VERSION "3.0.0"
+#define STRSCAN_VERSION "3.0.1"
 
 /* =======================================================================
                          Data Type Definitions