refactor(memory): use builtin strcat() instead of STRCAT()

The latter was mostly relevant with the past char_u madness.

NOTE: STRCAT also functioned as a counterfeit "NOLINT" for clint
apparently. But NOLINT-ing every usecase is just the same as disabling
the check entirely.

src/nvim/cmdexpand.c

@@ -3257,7 +3257,7 @@ void globpath(char *path, char *file, garray_T *ga, int expand_options, bool dir
     copy_option_part(&path, buf, MAXPATHL, ",");
     if (strlen(buf) + strlen(file) + 2 < MAXPATHL) {
       add_pathsep(buf);
-      STRCAT(buf, file);
+      strcat(buf, file);
 
       char **p;
       int num_p = 0;