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/major-image-bump.yaml

@@ -0,0 +1,57 @@
+suite: Dependency checks | Major image bumps
+release:
+  name: gitea-unittests
+  namespace: testing
+tests:
+  - it: "[postgresql-ha] ensures we detect major image version upgrades"
+    template: charts/postgresql-ha/templates/postgresql/statefulset.yaml
+    set:
+      postgresql:
+        enabled: false
+      postgresql-ha:
+        enabled: true
+    asserts:
+      - documentIndex: 0
+        matchRegex:
+          path: spec.template.spec.containers[0].image
+          # IN CASE OF AN INTENTIONAL MAJOR BUMP, ADJUST THIS TEST
+          pattern: bitnami/postgresql-repmgr:16.+$
+  - it: "[postgresql] ensures we detect major image version upgrades"
+    template: charts/postgresql/templates/primary/statefulset.yaml
+    set:
+      postgresql:
+        enabled: true
+      postgresql-ha:
+        enabled: false
+    asserts:
+      - documentIndex: 0
+        matchRegex:
+          path: spec.template.spec.containers[0].image
+          # IN CASE OF AN INTENTIONAL MAJOR BUMP, ADJUST THIS TEST
+          pattern: bitnami/postgresql:16.+$
+  - it: "[redis-cluster] ensures we detect major image version upgrades"
+    template: charts/redis-cluster/templates/redis-statefulset.yaml
+    set:
+      redis-cluster:
+        enabled: true
+      redis:
+        enabled: false
+    asserts:
+      - documentIndex: 0
+        matchRegex:
+          path: spec.template.spec.containers[0].image
+          # IN CASE OF AN INTENTIONAL MAJOR BUMP, ADJUST THIS TEST
+          pattern: bitnami/redis-cluster:7.+$
+  - it: "[redis] ensures we detect major image version upgrades"
+    template: charts/redis/templates/master/application.yaml
+    set:
+      redis-cluster:
+        enabled: false
+      redis:
+        enabled: true
+    asserts:
+      - documentIndex: 0
+        matchRegex:
+          path: spec.template.spec.containers[0].image
+          # IN CASE OF AN INTENTIONAL MAJOR BUMP, ADJUST THIS TEST
+          pattern: bitnami/redis:7.+$