MT#62714 build: allow to change pool_size via admin panel

We have a fixed value in config but for repoapi-dev it's just 1.
When doing tests, now that we have two slaves it's convenient to
be able to change that at will.

That could help too if we want to increase/decrease in the middle
of a already triggered build

Change-Id: I3c154ae2e3a754f995deb856e7b9b85ca1148107

build/admin.py

@@ -1,4 +1,4 @@
-# Copyright (C) 2017-2023 The Sipwise Team - http://sipwise.com
+# Copyright (C) 2017-2025 The Sipwise Team - http://sipwise.com
 #
 # This program is free software: you can redistribute it and/or modify it
 # under the terms of the GNU General Public License as published by the Free
@@ -34,7 +34,6 @@ class BuildReleaseAdmin(ImportExportModelAdmin, ExportActionModelAdmin):
         "triggered_projects",
         "built_projects",
         "failed_projects",
-        "pool_size",
         "triggered_jobs",
         "build_deps",
     )