Remove unnecessary void from definitions

The C templates had void in the parameter list of the definition of
functions that take no arguments, but these functions already have a
function prototype declared for them that has void in hte parameter
list, making it unnecessary to also have in the definition.

Author: friendlyanon

cmake-init/templates/c/executable/source/lib.c

@@ -1,6 +1,6 @@
 #include <lib.h>
 
-library create_library(void)
+library create_library()
 {
   library lib;
   lib.name = "%(name)s";

cmake-init/templates/c/header/include/__name__/__name__.h

@@ -10,7 +10,7 @@ extern "C" {
 const char* header_only_name(void);
 
 #ifdef %(uc_name)s_IMPLEMENTATION
-const char* header_only_name(void)
+const char* header_only_name()
 {
   return "%(name)s";
 }

cmake-init/templates/c/shared/source/__name__.c

@@ -1,6 +1,6 @@
 #include <%(name)s/%(name)s.h>
 
-const char* exported_function(void)
+const char* exported_function()
 {
   return "%(name)s";
 }