Re-add GPG configuration feature (#374)

This reverts d5ce1a47ea and therefore adds the GPG feature back into main.
As it is a breaking change, this PR now also contains the required upgrade notes.

Closes #107 again.

Co-authored-by: justusbunsi <sk.bunsenbrenner@gmail.com>
Reviewed-on: https://gitea.com/gitea/helm-chart/pulls/374
Reviewed-by: pat-s <pat-s@noreply.gitea.io>
Reviewed-by: John Olheiser <john+gitea@jolheiser.com>

unittests/statefulset/signing-disabled.yaml

@@ -0,0 +1,40 @@
+suite: Statefulset template (signing disabled)
+release:
+  name: gitea-unittests
+  namespace: testing
+templates:
+  - templates/gitea/statefulset.yaml
+  - templates/gitea/config.yaml
+tests:
+  - it: skips gpg init container
+    template: templates/gitea/statefulset.yaml
+    asserts:
+      - notContains:
+          path: spec.template.spec.initContainers
+          any: true
+          content:
+            name: configure-gpg
+  - it: skips gpg env in `init-directories` init container
+    template: templates/gitea/statefulset.yaml
+    set:
+      signing.enabled: true
+    asserts:
+      - contains:
+          path: spec.template.spec.initContainers[0].env
+          content:
+            name: GNUPGHOME
+            value: /data/git/.gnupg
+  - it: skips gpg env in runtime container
+    template: templates/gitea/statefulset.yaml
+    asserts:
+      - notContains:
+          path: spec.template.spec.containers[0].env
+          content:
+            name: GNUPGHOME
+  - it: skips gpg volume spec
+    template: templates/gitea/statefulset.yaml
+    asserts:
+      - notContains:
+          path: spec.template.spec.volumes
+          content:
+            name: gpg-private-key