feat: made compatible with OCP (OKD or OpenShift) (#953)

Reviewed-on: https://code.forgejo.org/forgejo-helm/forgejo-helm/pulls/953
Reviewed-by: Michael Kriese <michael.kriese@gmx.de>
Co-authored-by: Lucien Weller <lucien@wellernet.ch>
Co-committed-by: Lucien Weller <lucien@wellernet.ch>

unittests/deployment/security-context-normal.yaml

@@ -0,0 +1,25 @@
+# $schema: https://raw.githubusercontent.com/helm-unittest/helm-unittest/main/schema/helm-testsuite.json
+suite: deployment template (security context)
+release:
+  name: gitea-unittests
+  namespace: testing
+templates:
+  - templates/gitea/deployment.yaml
+  - templates/gitea/config.yaml
+tests:
+  - it: FS group set to 1000
+    template: templates/gitea/deployment.yaml
+    set:
+      image.rootless: false
+    asserts:
+      - equal:
+          path: spec.template.spec.securityContext.fsGroup
+          value: 1000
+  - it: run configure-gitea with UID 1000
+    template: templates/gitea/deployment.yaml
+    set:
+      image.rootless: false
+    asserts:
+      - equal:
+          path: spec.template.spec.initContainers[?(@.name == 'configure-gitea')].securityContext.runAsUser
+          value: 1000