meson: Add missing argument to gssapi.h check

These were missing since the initial introduction of the meson based build, in
e6927270cd. As-is this is unlikely to cause an issue, but a future commit
will add support for detecting gssapi without use of dependency(), which could
fail due to this.

Discussion: https://postgr.es/m/20240708225659.gmyqoosi7km6ysgn@awork3.anarazel.de
Backpatch: 16-, where the meson based build was added

meson.build

@@ -621,7 +621,8 @@ if not gssapiopt.disabled()
   elif cc.check_header('gssapi/gssapi.h', dependencies: gssapi, required: false,
       args: test_c_args, include_directories: postgres_inc)
     cdata.set('HAVE_GSSAPI_GSSAPI_H', 1)
-  elif cc.check_header('gssapi.h', args: test_c_args, dependencies: gssapi, required: gssapiopt)
+  elif cc.check_header('gssapi.h', dependencies: gssapi, required: gssapiopt,
+      args: test_c_args, include_directories: postgres_inc)
     cdata.set('HAVE_GSSAPI_H', 1)
   else
     have_gssapi = false
@@ -631,7 +632,8 @@ if not gssapiopt.disabled()
   elif cc.check_header('gssapi/gssapi_ext.h', dependencies: gssapi, required: false,
       args: test_c_args, include_directories: postgres_inc)
     cdata.set('HAVE_GSSAPI_GSSAPI_EXT_H', 1)
-  elif cc.check_header('gssapi_ext.h', args: test_c_args, dependencies: gssapi, required: gssapiopt)
+  elif cc.check_header('gssapi_ext.h', dependencies: gssapi, required: gssapiopt,
+      args: test_c_args, include_directories: postgres_inc)
     cdata.set('HAVE_GSSAPI_EXT_H', 1)
   else
     have_gssapi = false