Core(fix): remove bool typedef in C23

[pastalian]

In C23 (the default for GCC 15), bool is a keyword, so typedef needs to be removed.

../srain-1.8.0/src/inc/srain.h:26:18: error: two or more data types in declaration specifiers
   26 | typedef gboolean bool;
      |                  ^~~~

../srain-1.8.0/src/filter/user_filter.c:32:15: error: initialization of ‘SrnRet (*)(const SrnMessage *)’ {aka ‘int (*)(const struct _SrnMessage *)’} from incompatible pointe
r type ‘_Bool (*)(const SrnMessage *)’ {aka ‘_Bool (*)(const struct _SrnMessage *)’} [-Wincompatible-pointer-types]
   32 |     .filter = filter,
      |               ^~~~~~

Also fixes an oversight in 7f27c41.

../srain-1.8.0/src/core/app.c: In function ‘srn_application_add_server’:
../srain-1.8.0/src/core/app.c:237:15: error: too many arguments to function ‘srn_server_config_new’
  237 |     srv_cfg = srn_server_config_new(name);
      |               ^~~~~~~~~~~~~~~~~~~~~

Downstream Bug: https://bugs.gentoo.org/945702

[SilverRainZ]

Thank you~