[BUG] Don't allow owner team with incorrect unit access

- On editting a team, only update the units if the team isn't the
'Owners' team. Otherwise the 'Owners' team end up having all of their
unit access modes set to 'None'; because the request form doesn't send
over any units, as it's simply not shown in the UI.
- Adds a database inconstency check and fix for the case where the
'Owners' team is affected by this bug.
- Adds unit test.
- Adds integration test.
- Resolves #5528
- Regression of https://github.com/go-gitea/gitea/pull/24012

models/organization/TestInconsistentOwnerTeam/team.yml

@@ -0,0 +1,10 @@
+-
+  id: 1000
+  org_id: 1000
+  lower_name: owners
+  name: Owners
+  authorize: 4 # owner
+  num_repos: 0
+  num_members: 0
+  includes_all_repositories: true
+  can_create_org_repo: true

models/organization/TestInconsistentOwnerTeam/team_unit.yml

@@ -0,0 +1,59 @@
+-
+  id: 1000
+  team_id: 1000
+  type: 1
+  access_mode: 0 # None
+
+-
+  id: 1001
+  team_id: 1000
+  type: 2
+  access_mode: 0
+
+-
+  id: 1002
+  team_id: 1000
+  type: 3
+  access_mode: 0
+
+-
+  id: 1003
+  team_id: 1000
+  type: 4
+  access_mode: 0
+
+-
+  id: 1004
+  team_id: 1000
+  type: 5
+  access_mode: 0
+
+-
+  id: 1005
+  team_id: 1000
+  type: 6
+  access_mode: 0
+
+-
+  id: 1006
+  team_id: 1000
+  type: 7
+  access_mode: 0
+
+-
+  id: 1007
+  team_id: 1000
+  type: 8
+  access_mode: 0
+
+-
+  id: 1008
+  team_id: 1000
+  type: 9
+  access_mode: 0
+
+-
+  id: 1009
+  team_id: 1000
+  type: 10
+  access_mode: 0