refactor!: move openshift.hostUsers to deployment.hostUsers

The PodSpec `hostUsers` field has nothing to do with the OpenShift compatibility profile. It only selects whether the
pod shares the host's user namespace, which is a plain Kubernetes feature. Nesting it below `openshift` implied that it
requires OpenShift and, worse, the helper only rendered it when `openshift.enabled` evaluated to `true`, so the setting
was silently ignored on vanilla Kubernetes clusters.

`gitea.hostUsers` now reads `deployment.hostUsers` and no longer depends on the OpenShift profile. The value is only
rendered when it is an actual boolean, so the field stays omitted for `null` and the platform default applies.

BREAKING CHANGE: `openshift.hostUsers` has been removed. Configure `deployment.hostUsers` instead.

Co-authored-by: Copilot <copilot@github.com>

unittests/helm/deployment/openshift.yaml

@@ -79,8 +79,8 @@ tests:
     set:
       openshift:
         enabled: true
-        hostUsers: true
       deployment:
+        hostUsers: true
         securityContext:
           fsGroup: 1000620000
         gitea:
@@ -107,6 +107,7 @@ tests:
     set:
       openshift:
         enabled: true
+      deployment:
         hostUsers: false
     asserts:
       - equal: