Ensure default customization of Chart dependencies (#748)

### Description of the change

This adds unittests for the default configuration of our dependencies.

### Benefits

We are able to detect changes in upstream Charts for those settings.

### Applicable issues

- fixes #409

### Additional information

I merged existing unittests with the new ones for `postgresql-ha` and `postgresql`.
However, I decided to not do this for `redis-cluster` and `redis`, because the existing tests[^1] also ensure how the Chart behaves when both redis dependencies are disabled. It didn't felt right to split those files.

### Checklist

- [x] Templating unittests are added

Signed-off-by: justusbunsi <sk.bunsenbrenner@gmail.com>

[^1]: e733287dc2/unittests/config/cache-config.yaml, e733287dc2/unittests/config/queue-config.yaml, e733287dc2/unittests/config/session-config.yaml

Reviewed-on: https://gitea.com/gitea/helm-chart/pulls/748
Co-authored-by: justusbunsi <sk.bunsenbrenner@gmail.com>
Co-committed-by: justusbunsi <sk.bunsenbrenner@gmail.com>

unittests/dependency-checks/customization-integrity-redis-cluster.yaml

@@ -0,0 +1,90 @@
+suite: Dependency checks | Customization integrity | redis-cluster
+release:
+  name: gitea-unittests
+  namespace: testing
+set:
+  redis:
+    enabled: false
+  redis-cluster:
+    enabled: true
+    usePassword: false
+    cluster:
+      nodes: 5
+      replicas: 2
+tests:
+  - it: "[redis-cluster] configures correct nodes/replicas"
+    template: charts/redis-cluster/templates/redis-statefulset.yaml
+    asserts:
+      - documentIndex: 0
+        equal:
+          path: spec.replicas
+          value: 5
+      - documentIndex: 0
+        matchRegex:
+          path: spec.template.spec.containers[0].args[0]
+          pattern: REDIS_CLUSTER_REPLICAS="2"
+  - it: "[redis-cluster] support auth-less connections"
+    asserts:
+      - template: charts/redis-cluster/templates/secret.yaml
+        hasDocuments:
+          count: 0
+      - template: charts/redis-cluster/templates/redis-statefulset.yaml
+        documentIndex: 0
+        contains:
+          path: spec.template.spec.containers[0].env
+          content:
+            name: ALLOW_EMPTY_PASSWORD
+            value: "yes"
+  - it: "[redis-cluster] support auth-full connections"
+    set:
+      redis-cluster:
+        usePassword: true
+    asserts:
+      - template: charts/redis-cluster/templates/secret.yaml
+        containsDocument:
+          kind: Secret
+          apiVersion: v1
+          name: gitea-unittests-redis-cluster
+          namespace: testing
+      - template: charts/redis-cluster/templates/redis-statefulset.yaml
+        documentIndex: 0
+        contains:
+          path: spec.template.spec.containers[0].env
+          content:
+            name: REDISCLI_AUTH
+            valueFrom:
+              secretKeyRef:
+                name: gitea-unittests-redis-cluster
+                key: redis-password
+      - template: charts/redis-cluster/templates/redis-statefulset.yaml
+        documentIndex: 0
+        contains:
+          path: spec.template.spec.containers[0].env
+          content:
+            name: REDIS_PASSWORD
+            valueFrom:
+              secretKeyRef:
+                name: gitea-unittests-redis-cluster
+                key: redis-password
+  - it: "[redis-cluster] renders the referenced service"
+    template: charts/redis-cluster/templates/headless-svc.yaml
+    asserts:
+      - containsDocument:
+          kind: Service
+          apiVersion: v1
+          name: gitea-unittests-redis-cluster-headless
+          namespace: testing
+      - documentIndex: 0
+        contains:
+          path: spec.ports
+          content:
+            name: tcp-redis
+            port: 6379
+            targetPort: tcp-redis
+  - it: "[gitea] waits for redis-cluster to be up and running"
+    template: templates/gitea/init.yaml
+    asserts:
+      - documentIndex: 0
+        matchRegex:
+          path: stringData["configure_gitea.sh"]
+          pattern: nc -vz -w2 gitea-unittests-redis-cluster-headless.testing.svc.cluster.local 6379